A wind power generating device, characterized in that the wind power generating device comprises: a power source assembly which includes a rotor component and a brake component, the rotor component including a blade and a drive shaft, the blade being served to receive the wind force from the front side to rotate, the drive shaft being in driven connection with the blade to transfer the rotary motion of the blade, the brake component including a brake disc and a brake actuator, the brake disc being positioned at the back side of the blade and being configured to interlink with the blade so as to rotate together with the blade, wherein the brake actuator is provided with a lever, a wind collector and a brake pad, the lever is provided with a lever fulcrum in such a manner that the wind collector is provided at one end of the lever, the brake pad is provided at the other end of the lever, the lever fulcrum of the lever is located between the wind collector and the brake pad, and a wind force applying on the wind collector swings the lever by taking the lever fulcrum as the fulcrum, wherein a brake surface of the brake pad faces forward a direction where a wind is from so as to touch and brake the brake disc in such a manner that the wind collector and the brake pad move in opposite directions by taking the lever fulcrum as a fulcrum such that when the wind collector swings backward with the pushing of the wind force from the front side, the brake pad relatively swings forward to touch and brake the brake disc by means of the leverage of the brake actuator so as to apply a brake force in such a manner that the rotor component is braked; and a power generating assembly, which includes a power generating element, a maximum power point tracker (MPPT) and an energy storage element which are electrically connected to each other, the power generating element being in drive connection with the drive shaft such that the power generating element is driven by the drive shaft to generate electric energy, and the generated electric energy is stored to the energy storage element under the control of the maximum power point tracker. a power source assembly which includes a rotor component and a brake component, the rotor component including a blade and a drive shaft, the blade being served to receive the wind force from the front side to rotate, the drive shaft being in driven connection with the blade to transfer the rotary motion of the blade, the brake component including a brake disc and a brake actuator, the brake disc being positioned at the back side of the blade and being configured to interlink with the blade so as to rotate together with the blade, wherein the brake actuator is provided with a lever, a wind collector and a brake pad, the lever is provided with a lever fulcrum in such a manner that the wind collector is provided at one end of the lever, the brake pad is provided at the other end of the lever, the lever fulcrum of the lever is located between the wind collector and the brake pad, and a wind force applying on the wind collector swings the lever by taking the lever fulcrum as the fulcrum, wherein a brake surface of the brake pad faces forward a direction where a wind is from so as to touch and brake the brake disc in such a manner that the wind collector and the brake pad move in opposite directions by taking the lever fulcrum as a fulcrum such that when the wind collector swings backward with the pushing of the wind force from the front side, the brake pad relatively swings forward to touch and brake the brake disc by means of the leverage of the brake actuator so as to apply a brake force in such a manner that the rotor component is braked; and a power generating assembly, which includes a power generating element, a maximum power point tracker (MPPT) and an energy storage element which are electrically connected to each other, the power generating element being in drive connection with the drive shaft such that the power generating element is driven by the drive shaft to generate electric energy, and the generated electric energy is stored to the energy storage element under the control of the maximum power point tracker.