The utility model discloses an underwater equipment fast connecting and locking device, wherein the lower end of a push rod of an upper assembly extends into an inner cavity of an upper sleeve, the lower end of the upper sleeve is connected with the upper end of a lower sleeve through an upper bottom plate, the push rod passes through the upper sleeve and a center through hole of the upper bottom plate and extends into a cavity of the lower sleeve, the lower end of the push rod is sequentially provided with a conical sleeve and a position limiting disc, a first guide key is arranged on the surface of the outer circle of the conical sleeve, a first key slot is formed in the inner circle surface of the lower sleeve, the first guide key is clamped into the first key slot, a second key slot is additionally formed in the outer circle surface of the lower sleeve, a lower assembly comprises a lower bottom plate, a second guide key is arranged on the inner surface of a center annular hole of the lower bottom plate, the second key slot slides along the second guide key, and an annular groove is additionally formed in the inner surface of the center annular hole of the lower bottom plate. The underwater equipment fast connecting and locking device provided by the utility model has the advantages that the fast connection and locking on two sets of underwater equipment can be realized through one-step operation, the operation is simple and convenient, and the connection is fast and reliable.