This study presents a cavity quantum electrodynamics (QED) system where a two-level atom interacts with two counter-propagating modes of a whispering-gallery-mode (WGM) microcavity. The cavity is rotated at a certain angular velocity and directionally squeezed by a unidirectional parametric pumping nonlinearity. This setup enables nonreciprocal first- and second-order superradiant phase transitions, which do not require ultrastrong atom-field couplings and can be controlled by an external pump field. The system's phase diagram reveals two types of multicritical points, both exhibiting controllable nonreciprocity. These results open new possibilities for all-optical manipulation of superradiant transitions and multicritical behaviors in light-matter systems, with potential applications in integrated nonreciprocal quantum devices. The study explores the emergence of nonreciprocal superradiant phase transitions and multicriticality in a cavity QED system. The system consists of a two-level atom interacting with two counter-propagating modes of a WGM microcavity. The cavity is rotated and directionally squeezed by a unidirectional parametric pumping nonlinearity. This combination leads to nonreciprocal first- and second-order superradiant phase transitions. The system's phase diagram shows two types of multicritical points, both exhibiting controllable nonreciprocity. The study demonstrates that the nonreciprocal superradiant phase transitions can be achieved by tuning the external pump field, and the multicritical points can be manipulated with controllable nonreciprocity. The results suggest that this system could be used for all-optical manipulation of superradiant transitions and multicritical behaviors in light-matter systems, with potential applications in integrated nonreciprocal quantum devices.This study presents a cavity quantum electrodynamics (QED) system where a two-level atom interacts with two counter-propagating modes of a whispering-gallery-mode (WGM) microcavity. The cavity is rotated at a certain angular velocity and directionally squeezed by a unidirectional parametric pumping nonlinearity. This setup enables nonreciprocal first- and second-order superradiant phase transitions, which do not require ultrastrong atom-field couplings and can be controlled by an external pump field. The system's phase diagram reveals two types of multicritical points, both exhibiting controllable nonreciprocity. These results open new possibilities for all-optical manipulation of superradiant transitions and multicritical behaviors in light-matter systems, with potential applications in integrated nonreciprocal quantum devices. The study explores the emergence of nonreciprocal superradiant phase transitions and multicriticality in a cavity QED system. The system consists of a two-level atom interacting with two counter-propagating modes of a WGM microcavity. The cavity is rotated and directionally squeezed by a unidirectional parametric pumping nonlinearity. This combination leads to nonreciprocal first- and second-order superradiant phase transitions. The system's phase diagram shows two types of multicritical points, both exhibiting controllable nonreciprocity. The study demonstrates that the nonreciprocal superradiant phase transitions can be achieved by tuning the external pump field, and the multicritical points can be manipulated with controllable nonreciprocity. The results suggest that this system could be used for all-optical manipulation of superradiant transitions and multicritical behaviors in light-matter systems, with potential applications in integrated nonreciprocal quantum devices.