Additive manufacturing method for large precipitation hardening stainless steel hollow shaft

The invention relates to an additive manufacturing method for a large precipitation-hardening stainless steel hollow shaft. Large components manufactured through electric arc additive manufacturing are large in stress and prone to cracking in the cladding process, and how to effectively control stress and deformation is the problem faced by large hollow shafts manufactured through electric arc additive manufacturing. The invention provides an electric arc additive manufacturing method for a large precipitation-hardening stainless steel hollow shaft, which comprises the following steps of: forming the large precipitation-hardening stainless steel hollow shaft in sections, carrying out stress relief annealing and inner cavity surface machining on each section after carrying out electric arc additive forming, then carrying out integral heat treatment on the adjustment, and finally removing the allowance by adopting a machining mode. The hollow shaft to be formed is composed of an inner cylinder, an outer cylinde