A valve, comprising: a valve body comprising a fluid channel, the fluid channel comprising a first end and a second end; a barrier disposed in the fluid channel and separating the fluid channel into a first cavity and a second cavity, wherein the first cavity is in fluid communication with the first end, the second cavity is in fluid communication with the second end, and the barrier is provided with a first through hole and a second through hole communicating the first cavity and the second cavity; a first unidirectional valve core configured to close or open the first through hole; and a second unidirectional valve core configured to close or open the second through hole, opening directions of the first unidirectional valve core and the second unidirectional valve core being opposite such that a difference between a fluid pressure at the first end and a fluid pressure at the second end is within a preset range; characterized in that the valve further comprises: an elastic return member shared by the first unidirectional valve core and the second unidirectional valve core, the elastic return member tending to hold the first unidirectional valve core at a position closing the first through hole and hold the second unidirectional valve core at a position closing the second through hole; wherein the valve further comprises: a support base disposed in the first cavity and linked with the first unidirectional valve core; wherein the elastic return member is disposed in the first cavity, one end of the elastic return member abuts against the second unidirectional valve core, and an other end of the elastic return member abuts against the support base; wherein the first unidirectional valve core is disposed in the second cavity and the second unidirectional valve core is disposed in the first cavity; wherein the support base is in sliding fit with an inner wall of the fluid channel. a valve body comprising a fluid channel, the fluid channel comprising a first end and a second end; a barrier disposed in the fluid channel and separating the fluid channel into a first cavity and a second cavity, wherein the first cavity is in fluid communication with the first end, the second cavity is in fluid communication with the second end, and the barrier is provided with a first through hole and a second through hole communicating the first cavity and the second cavity; a first unidirectional valve core configured to close or open the first through hole; and a second unidirectional valve core configured to close or open the second through hole, opening directions of the first unidirectional valve core and the second unidirectional valve core being opposite such that a difference between a fluid pressure at the first end and a fluid pressure at the second end is within a preset range; characterized in that the valve further comprises: an elastic return member shared by the first unidirectional valve core and the second unidirectional valve core, the elastic return member tending to hold the first unidirectional valve core at a position closing the first through hole and hold the second unidirectional valve core at a position closing the second through hole; wherein the valve further comprises: a support base disposed in the first cavity and linked with the first unidirectional valve core; wherein the elastic return member is disposed in the first cavity, one end of the elastic return member abuts against the second unidirectional valve core, and an other end of the elastic return member abuts against the support base; wherein the first unidirectional valve core is disposed in the second cavity and the second unidirectional valve core is disposed in the first cavity; wherein the support base is in sliding fit with an inner wall of the fluid channel. an elastic return member shared by the first unidirectional valve core and the second unidirectional valve core, the elastic return member tending to hold the first unidirectional valve core at a position closing the first through hole and hold the second unidirectional valve core at a position closing the second through hole; wherein the valve further comprises: a support base disposed in the first cavity and linked with the first unidirectional valve core; wherein the elastic return member is disposed in the first cavity, one end of the elastic return member abuts against the second unidirectional valve core, and an other end of the elastic return member abuts against the support base; wherein the first unidirectional valve core is disposed in the second cavity and the second unidirectional valve core is disposed in the first cavity; wherein the support base is in sliding fit with an inner wall of the fluid channel. a support base disposed in the first cavity and linked with the first unidirectional valve core; wherein the elastic return member is disposed in the first cavity, one end of the elastic return member abuts against the second unidirectional valve core, and an other end of the elastic return member abuts against the support base; wherein the first unidirectional valve core is disposed in the second cavity and the second unidirectional valve core is disposed in the first cavity; wherein the support base is in sliding fit with an inner wall of the fluid channel.