The invention discloses a double-alternating check valve. The double-alternating check valve comprises a valve body, a first valve core assembly and a second valve core assembly, and the first valve core assembly comprises a first threaded sleeve in threaded connection with the valve body, a first valve sleeve in threaded connection with the first threaded sleeve, a first check valve base, a firstvalve base and a first valve core located in the first valve sleeve; the second valve core assembly includes a second threaded sleeve in threaded connection with the valve body, a second valve sleevein threaded connection with the second threaded sleeve, a second check valve base, a second valve base and a second valve core located in the second valve sleeve. According to the double-alternatingcheck valve, the valve bases, the valve sleeves and the threaded sleeves are integrally connected to form two insertion type valve core assemblies, and the two valve core assemblies are of an integrated structure, so that the system integration degree of the whole double-alternating check valve is high, the assembly and subsequent maintenance of the double-alternating check valve are facilitated,that is to say that the installation is simple and the maintenance is convenient, and the double-alternating check valve can be repaired directly by replacing the insertion type valve core assemblies.