With a 34.7 m catamaran fishing boat taken as the study object, according to requirements of relevant regulations of China Classification Society, finite element analysis method is presented for total structural strength of the catamaran fishing boat. The wave loads are calculated with direct calculation method and normative calculation method, thus to determine the input loads for analysis of the total structural strength of the catamaran fishing boat, establish the finite element model of the whole catamaran fishing boat’s structure, exert constraints and loads for analysis of the total strength, study the stress distribution of various parts of the hull, evaluate the key buckling strength of the cross structure, and analyse buckling strength characteristics of each member. The results show that the total structural strength of the catamaran fishing boat meets the requirements, the total transverse moment has the greatest influence on the total strength, the stress concentration appears at the junction between the cross structure’s front and aft end walls and the demihull, and the superstructure has a great impact on the transverse and torsional strength. This provides a reference for the design and construction of other catamaran fishing boats.