a slot, there are two left-right symmetrical slots, and the two slots are both provided on a server case base, and the two slots are respectively located on left and right sides of a fan;

an elastic arm assembly, the elastic arm assembly comprises two side arms which are left-right symmetrical and vertically arranged, and an elastic member, the two side arms are respectively located on left and right sides of the fan, bottoms of the two side arms are bent inwards to form bending regions, the two bending regions are respectively snap-fitted in the two slots, tops of the two side arms are connected by the elastic member;

a fixing assembly, the fixing assembly is provided with a limiting structure that fits with a mounting through hole on a top of a fan housing, and the fixing assembly is further provided with a sliding groove along a width direction of the fan; and

a pressing assembly, the pressing assembly is provided with a deformable region, and a sliding structure that fits with the sliding groove, the deformable region is configured to drive the sliding structure to move outwards in the sliding groove in respond to being subjected to an external force, and the sliding structure pushes the elastic member to stretch and deform, so that a distance between the two side arms increases to drive the bending regions of the two side arms to disengage from the two slots.