Abstract: The present disclosure relates to a transition method and system from helical winding to hoop winding of composite fibers. The method includes: setting a slip coefficient, and performing iterative calculation forward from an iteration starting point according to an equation set of a winding angle and a center angle of rotation to obtain a winding angle at an iteration termination point; and if the winding angle at the iteration termination point is greater than a first preset angle, adjusting the slip coefficient corresponding to a cylinder body according to the first preset angle, extending a length of a helical winding transition section to a front equator, and starting the hoop winding at the front equator at the first preset angle to complete planning of the helical winding transition section.