A controller for vehicle air conditioner, comprising: a base defining a mounting cavity; a knob assembly rotatably mounted to the base, wherein at least a portion of the knob assembly is located in the mounting cavity; and at least one bearing element (30, 40) arranged between the base and the knob assembly, wherein the controller for vehicle air conditioner further comprises: a spring element arranged between the base and the knob assembly, wherein the knob assembly comprises a shift portion which comprises a shift ring, the shift ring forms a plurality of convex portions and a plurality of concave portions which are alternately arranged, the spring element is connected with the base and extends into the concave portion of the shift ring, characterized in that the spring element comprises one selected from a group consisting of: a leaf spring comprising a fixing portion connected with the base and an engaging portion connected to the fixing portion, and the engaging portion extends to the concave portion of the shift ring; a spring in combination with a shift pin, wherein the spring is connected to the base, the shift pin is located at a distal end of the spring, and the shift pin is urged to the concave portion of the shift ring by the spring; and a spring in combination with a ball, wherein the spring is connected to the base, the ball is provided at a distal end of the spring, and the ball is urged to the concave portion of the shift ring by the spring. a base defining a mounting cavity; a knob assembly rotatably mounted to the base, wherein at least a portion of the knob assembly is located in the mounting cavity; and at least one bearing element (30, 40) arranged between the base and the knob assembly, wherein the controller for vehicle air conditioner further comprises: a spring element arranged between the base and the knob assembly, wherein the knob assembly comprises a shift portion which comprises a shift ring, the shift ring forms a plurality of convex portions and a plurality of concave portions which are alternately arranged, the spring element is connected with the base and extends into the concave portion of the shift ring, characterized in that the spring element comprises one selected from a group consisting of: a leaf spring comprising a fixing portion connected with the base and an engaging portion connected to the fixing portion, and the engaging portion extends to the concave portion of the shift ring; a spring in combination with a shift pin, wherein the spring is connected to the base, the shift pin is located at a distal end of the spring, and the shift pin is urged to the concave portion of the shift ring by the spring; and a spring in combination with a ball, wherein the spring is connected to the base, the ball is provided at a distal end of the spring, and the ball is urged to the concave portion of the shift ring by the spring. a leaf spring comprising a fixing portion connected with the base and an engaging portion connected to the fixing portion, and the engaging portion extends to the concave portion of the shift ring; a spring in combination with a shift pin, wherein the spring is connected to the base, the shift pin is located at a distal end of the spring, and the shift pin is urged to the concave portion of the shift ring by the spring; and a spring in combination with a ball, wherein the spring is connected to the base, the ball is provided at a distal end of the spring, and the ball is urged to the concave portion of the shift ring by the spring.