The invention provides a large-span wood truss roof construction method which comprises the following steps: S1, BIM simulation analysis: establishing a model through BIM, and analyzing a whole truss, node connection and a construction operation surface; s2, assembling is conducted, specifically, all parts of the wood truss are pre-assembled in a factory; s3, assembling jig frame arrangement, wherein an assembling jig frame is arranged on the construction site; s4, wood trusses are assembled on the ground; s5, the first wood truss is hoisted and installed; s6, setting a cable rope; s7, hoisting and mounting the truss; s8, connecting pieces are installed, wherein the connecting pieces are arranged between every two adjacent wood trusses; s9, cyclic operation is conducted, specifically, the steps S7 and S8 are repeated till all the wood trusses are hoisted; and S10, cross beams are installed, specifically, the cross beams are arranged between every two adjacent wood trusses, meanwhile, the corresponding connecting pieces are dismantled, and the problem that in the prior art, a large-span wood truss roof is not convenient to construct is solved.