The invention relates to a design method for a sub-steel clamping type saddle of a cable-stayed bridge. The design method includes the following specific steps of establishing a cable-stayed bridge structure calculation model and a saddle two-end unbalanced cable force calculation model, adopting a bridge structure calculation program to calculate the maximum unbalanced cable force at the two endsof the saddle and the corresponding cable force at the two ends of the saddle, conducting anti-slip safety factor calculation on the saddle with the known friction coefficient between cables and thesaddle under the maximum unbalanced cable force, and determining whether and how the sub-steel clamping type saddle is used according to the calculation result of anti-slip safety factors. The methodfor designing the saddle of the cable-stayed bridge according to the bearing requirements is provided, and the safety and rationality of design of the saddle of the cable-stayed bridge are improved.