A heat exchange device, comprising a heat exchanger body and a thermostatic assembly, wherein the heat exchanger body comprises a fluid inlet, a fluid outlet, a heat exchange passage, and a bypass passage, and the heat exchanger body further comprises a heat dissipation assembly, the heat dissipation assembly is provided with the heat exchange passage; the heat exchanger body further comprises a first passage, one end of the first passage is in communication with the fluid inlet, at least part of the thermostatic assembly is arranged in the first passage, the thermostatic assembly comprises a valve body provided with a valve chamber, the valve body is provided with an inlet, a first outlet, and a second outlet which are all in communication with the valve chamber; a return spring, a shape memory alloy spring, and a valve sleeve are provided in the valve chamber, the valve sleeve is slidable back and forth in an axial direction, the shape memory alloy spring is made of a shape memory alloy material, and the return spring and the shape memory alloy spring are respectively located on two sides of the valve sleeve; in a case that a temperature is lower than a predetermined temperature, an elastic function of the shape memory alloy spring is disabled, and under an action of the return spring, the valve sleeve is at a first position, and the inlet is in communication with the bypass passage through the second outlet; and in a case that the temperature is greater than or equal to the predetermined temperature, elastic potential energy of the shape memory alloy spring is activated, and an elastic force of the shape memory alloy spring is greater than an elastic force of the return spring, and under an action of an elastic force difference between the shape memory alloy spring and the return spring, the valve sleeve slides to a second position to close the second outlet, the first outlet is in communication with the heat exchange passage, and the inlet is in communication with the heat exchange passage through the first outlet, wherein the valve body is a hollow cylinder having a closed end at one end and an open end at another end, a valve seat is provided at the open end of the hollow cylinder, the valve seat is provided with a valve port, the inlet is in communication with the valve chamber through the valve port, and two ends of the return spring are respectively supported on the valve seat and the valve sleeve. the heat exchanger body further comprises a first passage, one end of the first passage is in communication with the fluid inlet, at least part of the thermostatic assembly is arranged in the first passage, the thermostatic assembly comprises a valve body provided with a valve chamber, the valve body is provided with an inlet, a first outlet, and a second outlet which are all in communication with the valve chamber; a return spring, a shape memory alloy spring, and a valve sleeve are provided in the valve chamber, the valve sleeve is slidable back and forth in an axial direction, the shape memory alloy spring is made of a shape memory alloy material, and the return spring and the shape memory alloy spring are respectively located on two sides of the valve sleeve; in a case that a temperature is lower than a predetermined temperature, an elastic function of the shape memory alloy spring is disabled, and under an action of the return spring, the valve sleeve is at a first position, and the inlet is in communication with the bypass passage through the second outlet; and in a case that the temperature is greater than or equal to the predetermined temperature, elastic potential energy of the shape memory alloy spring is activated, and an elastic force of the shape memory alloy spring is greater than an elastic force of the return spring, and under an action of an elastic force difference between the shape memory alloy spring and the return spring, the valve sleeve slides to a second position to close the second outlet, the first outlet is in communication with the heat exchange passage, and the inlet is in communication with the heat exchange passage through the first outlet, wherein the valve body is a hollow cylinder having a closed end at one end and an open end at another end, a valve seat is provided at the open end of the hollow cylinder, the valve seat is provided with a valve port, the inlet is in communication with the valve chamber through the valve port, and two ends of the return spring are respectively supported on the valve seat and the valve sleeve.