The invention discloses a tricot machine principal axis direction swinging control device, which includes a single direction shaft sleeved on the outer part of a main shaft, and a positioning shell sleeved on the outer part of the single direction shaft, the outer circle of the single direction shaft is fixed tightly on the positioning shell, a shell positioning mechanism and the positioning shell are connected, the shell positioning mechanism includes a positioning shaft and a shaft sleeve, the shaft sleeve runs through a main shaft case and is fixedly installed on the main shaft case, the positioning shaft is sleeved inside the shaft sleeve and is connected with the positioning shell screw thread.