The invention discloses a method for truss concrete injection construction. The method comprises the steps of collecting building requirements and designing a steel box bidirectional truss structure; applying finite element software to establish a structure model of a truss, and a lower layer building and an upper layer building which are connected with the truss; using the finite element software to perform mechanics checking on the model, and calculating a pressure value of the truss; simulating reinforcement after concrete injection into a high pressed section with the high pressure value of the truss; manufacturing the truss according to the model; and performing site construction. Through deep design, internal force of the truss is analyzed by application of the finite element software, a local internal concrete filling mode is adopted for the high pressed section of a chord member, so that the strength and stiffness of the truss are enhanced, and the bearing capacity of the transfer truss is improved. According to the construction method, the use efficiency of construction machinery is improved, and the construction period is shortened; the quality guarantee difficulty resulting from high stress of the chord member is solved; the cross section of the truss is unchanged, the bearing capacity of a truss body is improved, and the construction cost is reduced.