A supercapacitor and power battery with square housing are disclosed, include a housing, A plurality of pressure grooves and projections are uniformly arranged on the shell, An upper end of the housing is connected with an end cap, the left and right sides of the end cover are respectively connected with a positive electrode aluminum plate and a negative electrode aluminum plate, the positive electrode aluminum plate comprises a positive electrode aluminum plate located on the outer side of the end cover and a positive electrode aluminum plate located on the inner side of the end cover, The negative electrode aluminum plate comprises a negative electrode aluminum plate 1 located on the outer side of the end cover and a negative electrode aluminum plate 2 located on the end cover body. Themiddle part of the end cover is provided with an explosion-proof valve mounting hole, and an explosion-proof valve is installed in the explosion-proof valve mounting hole. The end cover and the positive electrode aluminum plate 2 are connected with a positive electrode current collecting plate, and the end cover and the negative electrode aluminum plate 2 are connected with a negative electrode current collecting plate. The supercapacitor and the power battery of the invention have the advantages of simple structure, and the gas in the supercapacitor and the power battery can be discharged tothe outside in time, so that the service life of the supercapacitor and the power battery can be prolonged.