The invention belongs to the technical field of heliostats, and particularly relates to a heliostat used by a solar power generating system. The heliostat comprises a drive shaft, a speed reducer, aninput shaft, a first fixing board, a second fixing board, a ring disc, a heliostat body, a round disc, a fixing ring, a gear ring, a first drive gear, a first one-way clutch ring, a second drive gear,a second one-way clutch ring, a first shaft, a first L-type board, a first shaft sleeve and the like. The first one-way clutch ring and the second one-way clutch ring make a first crank rocker mechanism and a second crank rocker mechanism work under different conditions of rotation of a motor, and then the heliostat swings in azimuth angle and elevation angle and keeps the proper angle with the sun all the time. By reducing one motor and one heliostat, the heliostat device achieves the same effect with a traditional heliostat device, so that the economic cost is reduced and resources are saved.