The invention discloses a dynamic pressure spindle stiffness test system. The system includes a force receiving module, a fixing bearing sleeve, a fixing module, a load applying module, a force measurement module, a displacement measurement module and a control module; the force receiving module is provided with a dynamic pressure spindle, and the periphery of the dynamic pressure spindle is sleeved with a bearing, an outer ring of the bearing is sleeved with the fixing bearing sleeve, and the fixing bearing sleeve is provided with a hook used for disposing the weight for the force receiving module; fixing module is arranged below the force receiving module; the load applying module is arranged on the fixing module and used for applying a load to the bearing; the force measurement module is arranged on the load applying module and used for measuring the load F applied by the load applying module to the bearing; the displacement measurement module is opposite to the dynamic pressure spindle and used for measuring the radial displacement S of the dynamic pressure spindle; the control module is connected with the load applying module, the force measurement module and the displacement measurement module respectively and receives output signals of the force measurement module and the displacement measurement module so as to calculate the stiffness K=F/S of the dynamic pressure spindle. According to the dynamic pressure spindle stiffness test system, the safety is high and the measurement accuracy is high.