The invention discloses a shelter and flat truck body locking device. The shelter and flat truck body locking device comprises multiple limiting pins, multiple cross shafts, multiple locking hooks and a connecting rod mechanism, wherein the multiple cross shafts are suspended under a flat truck frame; the upper ends of the multiple locking pins respectively stretch out of the upper side of the flat truck frame and correspond to the positions of locking blocks arranged at the lower sides of vehicle-mounted shelters; the middle parts of the locking hooks are fixedly connected with the cross shafts; the connecting rod mechanism is arranged at the lower sides of the cross shafts; one end of a screw rod is arranged in supporting seats in a supporting way; the other end of the screw rod is overlapped with a nut seat in a screwing way; multiple supporting seats and one nut seat are respectively and fixedly arranged at the lower side of the flat truck frame; the end head of the other end of the screw rod is fixedly connected with one end of a polished rod; the polished rod is suspended under the flat truck frame through the multiple supporting seats; one end of each of multiple sliding cross pins is respectively, vertically and fixedly connected with the polished rod; the other end of each of the multiple sliding cross pins is respectively connected with the lower part of the corresponding locking hook in a sliding way. According to the shelter and flat truck body locking device disclosed by the invention, the structure is compact, the use is convenient, and locking or unlocking of multiple shelters can be completed through once operation; the locking is safe and reliable, the unlocking is very convenient, and the working efficiency of the shelter and flat truck body locking device is greatly increased.