A new type of cascade H-bridge pv module structure is proposed, which integrates pv module, Boost/Buck circuit, super capacitor and chain H-bridge circuit. The range of supercapacitor charge and discharge is analyzed and its inertial energy is calculated, and then put forward the control strategy of cascaded H-bridge. A 12H bridge cascade simulation model was built in EMTP to verify the operation of the full chain and lack chain of the cascade H-bridge and the dc side voltage inertia support. Finally, the experiment proves that the new cascade h-bridge photovoltaic module has the function of inertial energy support, which is of practical significance to improve the friendliness of photovoltaic power grid.