The study investigates the control of magnetic properties in monolayer and bilayer CrI3 using electrostatic doping through a dual-gate field-effect device structure. In monolayer CrI3, doping significantly modifies the saturation magnetization, coercive force, and Curie temperature, with hole doping strengthening and electron doping weakening magnetic order. In bilayer CrI3, doping drastically changes the interlayer magnetic order, transitioning from an antiferromagnetic to a ferromagnetic state above a critical electron density. This transition is attributed to a strongly doping-dependent interlayer exchange coupling, enabling robust magnetization switching by small gate voltages. The findings provide a basis for voltage-controlled spintronic and memory devices based on 2D magnetic materials, highlighting the potential for low-power, high-speed, and compatible magnetic switching applications.The study investigates the control of magnetic properties in monolayer and bilayer CrI3 using electrostatic doping through a dual-gate field-effect device structure. In monolayer CrI3, doping significantly modifies the saturation magnetization, coercive force, and Curie temperature, with hole doping strengthening and electron doping weakening magnetic order. In bilayer CrI3, doping drastically changes the interlayer magnetic order, transitioning from an antiferromagnetic to a ferromagnetic state above a critical electron density. This transition is attributed to a strongly doping-dependent interlayer exchange coupling, enabling robust magnetization switching by small gate voltages. The findings provide a basis for voltage-controlled spintronic and memory devices based on 2D magnetic materials, highlighting the potential for low-power, high-speed, and compatible magnetic switching applications.