The invention discloses spinning solvent circulating equipment for producing polypropylene threads by a dry method, and relates to the field of polypropylene thread production. The spinning solvent circulating equipment comprises a spinning channel, the spinning channel comprises a curing channel and a discharging channel which are separated by a sealed thread outlet mechanism, the curing channel communicates with a solvent supply cylinder, the solvent supply cylinder communicates with a hot air supply pipe, the other end of the hot air supply pipe communicates with an air storage cylinder, the air storage cylinder communicates with the curing channel through an exhaust mechanism, a communicating vessel is arranged in the solvent supply cylinder, the end, with the smaller diameter, of the communicating vessel communicates with the hot air supply pipe, so that internal circulation can be realized, volatile solvents are prevented from overflowing, the exhaust mechanism is adopted to exhaust part of gas in the curing channel, so that the pressure in the curing channel is reduced, the solvent is easier to volatilize, and the polypropylene fiber is easier to cure in a lower-temperature environment.