The three-dimensional standard vibrator based on leaf-spring-type decoupling device contains a base set with three single-dimensional vibrators (along X, Y and Z axes, respectively) and a three-dimensional vibration platform. The X axis vibrator is connected with the three-dimensional vibration platform through X axis decoupling device, the Y axis vibrator is connected with the three-dimensional vibration platform through Y axis decoupling device, and the Z axis vibrator is connected with the three-dimensional vibration platform through Z axis decoupling device. The properties of the three-dimensional vibrator are as follow. X axis decoupling device, Y axis decoupling device and Z axis decoupling device are all comprised of supporting-spring units. Each of the supporting-spring units contains a pair of leaf springs mounted parallel with each other and the first and second connecting components mounted on the two edges of the leaf springs. The first connecting component is near the vibrator and the second connecting component is near the three-dimensional vibration platform.