The invention discloses an electromagnetically controlled tee-joint flow valve and a medical breathing machine. The electromagnetically controlled tee-joint flow valve comprises an air source opening, a releasing opening and a breathing opening, wherein an inspiration valve is arranged between the air source opening and the breathing opening, an expiration valve is arranged between the breathing opening and the releasing opening, the inspiration valve and the expiration valve are regulated in a linkage relationship, are of a hollowed cylindrical nested structure and respectively comprise a fixing cylinder and a sliding cylinder which are nested together, and the sliding cylinders of the inspiration valve and the expiration valve are connected with electromagnetic drivers so as to realize synchronous control on opening degrees of the inspiration valve and the expiration valve. The medical breathing machine can control pressure and flow of inspiration and expiration by regulating the opening degrees of the inspiration valve and the expiration valve after being connected with the electromagnetically controlled tee-joint flow valve so as to maintain the suitable pressure or flow during inspiration and expiration, thus double-level pressure control and flow control of the medical breathing machine is realized; in addition, the medical breathing machine has the advantages of simple structure, convenience for using, exactness in control and capability of reducing power consumption.