The embodiment of the invention discloses a battery charging and discharging circuit, comprising: a battery module (1), configured to receive charging voltage or release discharging voltage; a transformer circuit (2), connected with the battery module (1), the transformer circuit (2) is configured to convert a first charging voltage into a charging voltage or convert a discharging voltage into a first discharging voltage; a buck-boost circuit (3), connected with the transformer circuit (2), the buck-boost circuit (3) is configured to convert a second charging voltage into the first charging voltage or convert the first discharging voltage into a second discharging voltage; a power grid end or user end (4), connected with the buck-boost circuit (3), the power grid end or user end (4) is configured to generate the second charging voltage or receive the second discharging voltage.