A charging method, comprising: acquiring a state parameter of a power battery by a power conversion apparatus, the state parameter comprising a battery temperature; setting a charging mode to a pulse charging mode by the power conversion apparatus based on the battery temperature being lower than a first preset threshold; and converting charging power to be received from a charging pile and then charging the power battery by the power conversion apparatus in the pulse charging mode, the pulse charging mode being a charging mode outputting a pulsed voltage or a pulsed current; wherein before setting a charging mode to the pulse charging mode by the power conversion apparatus, the method further comprises: sending a battery charging demand message to the charging pile by the power conversion apparatus, the battery charging demand message comprising a demand current being set as the minimum current of the charging pile that can be output; after sending the battery charging demand message, sending a charging prohibition message to the charging pile by the power conversion apparatus, the charging prohibition message being configured to indicate the charging pile to stop outputting a direct current to the power conversion apparatus; wherein the power conversion apparatus comprises a power unit and a control unit, and said power unit comprises a power conversion module, a first relay, a second relay and a third relay, the charging pile and the power battery are connected with each other through the first relay, the power conversion module of the power conversion apparatus is respectively connected to the charging pile and the power battery through the second relay and the third relay, and when the second relay and the third relay are both disconnected and the first relay is closed, the charging power output by the charging pile directly is transmitted to the power battery; wherein the setting a charging mode to a pulse charging mode by the power conversion apparatus based on the battery temperature is lower than a first preset threshold comprises: controlling the second relay and the third relay to be closed and the first relay to be disconnected, and setting the charging mode to the pulse charging mode by the power conversion apparatus based on the battery temperature being lower than the first preset threshold. acquiring a state parameter of a power battery by a power conversion apparatus, the state parameter comprising a battery temperature; setting a charging mode to a pulse charging mode by the power conversion apparatus based on the battery temperature being lower than a first preset threshold; and converting charging power to be received from a charging pile and then charging the power battery by the power conversion apparatus in the pulse charging mode, the pulse charging mode being a charging mode outputting a pulsed voltage or a pulsed current; wherein before setting a charging mode to the pulse charging mode by the power conversion apparatus, the method further comprises: sending a battery charging demand message to the charging pile by the power conversion apparatus, the battery charging demand message comprising a demand current being set as the minimum current of the charging pile that can be output; after sending the battery charging demand message, sending a charging prohibition message to the charging pile by the power conversion apparatus, the charging prohibition message being configured to indicate the charging pile to stop outputting a direct current to the power conversion apparatus; wherein the power conversion apparatus comprises a power unit and a control unit, and said power unit comprises a power conversion module, a first relay, a second relay and a third relay, the charging pile and the power battery are connected with each other through the first relay, the power conversion module of the power conversion apparatus is respectively connected to the charging pile and the power battery through the second relay and the third relay, and when the second relay and the third relay are both disconnected and the first relay is closed, the charging power output by the charging pile directly is transmitted to the power battery; wherein the setting a charging mode to a pulse charging mode by the power conversion apparatus based on the battery temperature is lower than a first preset threshold comprises: controlling the second relay and the third relay to be closed and the first relay to be disconnected, and setting the charging mode to the pulse charging mode by the power conversion apparatus based on the battery temperature being lower than the first preset threshold.