In order to solve the problem of the current propellant cutting device:the antiexplosion grade was low,and the cutting section was “horseshoe”,an antiexplosion vortex line online cutoff device was designed.The cutting process of the propellant was described and the mechanical structure and control system were designed.For the cutting device,ring line feeding mode was adopted,by which the propellant was cut with fixedlength.It was characterized that crank slider mechanism was used to clamp material.At the same time,the planetary wheel mechanism was used to cut off the material by the vortex line feed.The whole equipment adopts full pneumatic control and mechanical interlock to improve the safety performance of the device in the working environment of explosive dust.