The utility model relates to a two-stage tandem launching simulation test device for a composite material fragile cover and belongs to the technical field of missile launching. The test device comprises a base, a one-stage test barrel (internal), a two-stage test barrel (external), an inner guardrail, a sealing washer, metal pressing rings, gas-pressure meters and a gas pump, wherein the one-stage test barrel, the inner guardrail and the two-stage test barrel are mounted on the base; the gas-pressure meters and the gas pump are connected with the base through gas guide pipes. Compared with the prior art, the test device is simple in structure, convenient to maintain, and capable of completing an experimental goal conveniently, the cover opening pressure can be adjusted conveniently, the cover opening process and performance of the composite material fragile cover can be accurately simulated during missile launching, the test cost is effectively reduced, and effectiveness and rationality of the structural design of the composite material fragile cover are improved.