A four-function light electric hammer includes a body, a motor, a cylinder assemble, a big gear (23) and a torque clutch (2), a transmission mechanism, an operation mechanism and a knob (19). Said transmission mechanism includes a small gear (4), a hammering clutch (5), an intermediate shaft (6), a hammering clutch (7), a swing link bearing (8) and a first level gear (9). The small gear (4) is movably fit with the intermediate shaft (6). The small gear (4) meshes with the big gear (23) and matches with the internal teeth of the drilling clutch (5). The drilling clutch (5) and the hammering clutch (7) are movably fit with the intermediate shaft (6). The swing link bearing (8) is movably fit with the intermediate shaft (6) and connects with the cylinder assemble (3). The hammering clutch (7) and the swing link bearing (8) match with each other. The first level gear (9) is closely fit with the intermediate shaft (6).