A boiling flour-mixing machine comprises a body, an actuating device, a mixing rod shaft and a mixing rod arranged on the mixing rod shaft. The body comprises a main body and a cover arranged on the main body which is provided with a containing cavity for containing flour with an upward opening, the mixing rod shaft is arranged on two sides of the main body, and the mixing rod is arranged inside the containing cavity of the main body, with the containing cavity connected with a high temperature water vapor source through a vapor inlet. The upper end face of the main body contacting the cover is provided with an inner groove and an outer groove which are not connected and arranged on the periphery along the upper end face of the main body, a sealing ring is arranged in the outer groove, and a vapor discharging hole communicated with outside is opened on the inner groove. The boiling flour-mixing machine of the invention has the beneficial effects that when boiling and mixing flour, aqueous vapor and flour can not overflow out from the gap between the cover and the main body to influence environmental sanitation, increase temperature outside the boiling flour-mixing machine, deteriorate operating environment and scald people, and aqueous vapor can be discharged from the vapor discharging hole to avoid hypertension in the containing cavity from causing accidents.