The invention provides a railway wagon hoisting device and an operating method, and relates to the technical field of hoisting appliances. The railway wagon hoisting device comprises a hoisting frame,a positioning frame and at least two lazy arms. A first through hole is formed in the middle of the hoisting frame. A to-be-hoisted bottom frame penetrates through the hoisting frame via the first through hole. The hoisting frame is used for supporting the to-be-hoisted bottom frame, and a hoisting shaft is arranged on the hoisting frame. The positioning frame is movably connected with the hoisting frame and is used for adjusting and fixing the position of the to-be-hoisted bottom frame. One end of each lazy arm is connected with a hoisting appliance, and the other end of each lazy arm is connected with the hoisting shaft. Compared with the prior art, the railway wagon hoisting device and the operating method have the advantages that in-site supporting and movement and forward turning ofthe to-be-hoisted bottom frame can be achieved, the assembly welding efficiency and assembling efficiency of the to-be-hoisted bottom frame are improved, and the safety is good.