This paper explores the strain-induced control of anisotropic electrical conductance in phosphorene and few-layer black phosphorus. Through first-principles simulations, the authors demonstrate that biaxial or uniaxial strain can rotate the preferred conducting direction by 90 degrees. This manipulation is achieved by changing the energy order of the first and second lowest-energy conduction bands, which results in a switch in the effective mass of electrons and holes. The study shows that the anisotropic effective mass and mobility can be tuned within a strain range that is well within current experimental capabilities. This discovery opens up new possibilities for exploring quantum Hall effects and developing novel mechanical-electronic devices based on phosphorene. The findings highlight the potential of phosphorene as a promising material for high-performance applications.This paper explores the strain-induced control of anisotropic electrical conductance in phosphorene and few-layer black phosphorus. Through first-principles simulations, the authors demonstrate that biaxial or uniaxial strain can rotate the preferred conducting direction by 90 degrees. This manipulation is achieved by changing the energy order of the first and second lowest-energy conduction bands, which results in a switch in the effective mass of electrons and holes. The study shows that the anisotropic effective mass and mobility can be tuned within a strain range that is well within current experimental capabilities. This discovery opens up new possibilities for exploring quantum Hall effects and developing novel mechanical-electronic devices based on phosphorene. The findings highlight the potential of phosphorene as a promising material for high-performance applications.