A heat dissipation device comprising a heat absorbing member configured to absorb heat from a heat source, the heat absorbing member being provided with a first accommodating chamber for accommodating a phase change working medium, wherein the heat absorbing member is further provided with a mounting hole in communication with the first accommodating chamber, and the heat dissipation device further comprises a valve installed in the mounting hole of the heat absorbing member, the valve being adjustable between a first state and a second state to cause the first accommodating chamber to change between a closed state and an open state; wherein when the first accommodating chamber is in the open state, the first accommodating chamber is in fluid communication with outside the first accommodating chamber so that the phase change working medium can be injected into the first accommodating chamber via the mounting hole or discharged from the first accommodating chamber via the mounting hole; when the first accommodating chamber is in the closed state, the first accommodating chamber is sealed and isolated from outside the first accommodating chamber; the heat dissipation device further comprises a heat dissipating member made of a heat conductive material and connected to the heat absorbing member; characterized in that the heat dissipation device further comprises heat dissipating fins connected to the heat dissipating member; and a cover plate is arranged at an end of the heat dissipating member away from the heat absorbing member, and the heat dissipating fins are stacked between the heat absorbing member and the cover plate; a side of the cover plate facing the heat dissipating members is provided with positioning protrusions, and the heat dissipating member is correspondingly provided with positioning grooves for receiving the positioning protrusions respectively; a passage in fluid communication with the first accommodating chamber is provided inside the heat dissipating member. the heat absorbing member is further provided with a mounting hole in communication with the first accommodating chamber, and the heat dissipation device further comprises a valve installed in the mounting hole of the heat absorbing member, the valve being adjustable between a first state and a second state to cause the first accommodating chamber to change between a closed state and an open state; wherein when the first accommodating chamber is in the open state, the first accommodating chamber is in fluid communication with outside the first accommodating chamber so that the phase change working medium can be injected into the first accommodating chamber via the mounting hole or discharged from the first accommodating chamber via the mounting hole; when the first accommodating chamber is in the closed state, the first accommodating chamber is sealed and isolated from outside the first accommodating chamber; the heat dissipation device further comprises a heat dissipating member made of a heat conductive material and connected to the heat absorbing member; characterized in that the heat dissipation device further comprises heat dissipating fins connected to the heat dissipating member; and a cover plate is arranged at an end of the heat dissipating member away from the heat absorbing member, and the heat dissipating fins are stacked between the heat absorbing member and the cover plate; a side of the cover plate facing the heat dissipating members is provided with positioning protrusions, and the heat dissipating member is correspondingly provided with positioning grooves for receiving the positioning protrusions respectively; a passage in fluid communication with the first accommodating chamber is provided inside the heat dissipating member.