A thermostatic valve includes a housing internally provided with a receiving cavity and a thermostatic actuating element mounted in the receiving cavity. The receiving cavity is in communication with the exterior through at least three ports such as a first connecting port, a second connecting port, and a third connecting port. The thermostatic actuating element is mounted in the housing via two elastic members. An annular sealing collar which is fixedly mounted is provided in the receiving cavity. At least most of the thermostatic actuating element is located between the third port and the sealing collar. Such arrangement may ensure the temperature of the transmission oil when having a low temperature can rise rapidly and ensure the lubrication performance of a transmission. In addition, a processing precision requirement for components and parts can be reduced and manufacturing and mounting are more convenient.