During the design of a turbofan engine measuring rake, it was found that the existing strength analysis method was quite different from the actual engine flow conditions, made it hard to simulate the real load on the rake in the engine runner. To solve the above problems, a unidirectional fluid-structure interaction method is proposed. It is found that the load calculated by the unidirectional fluid-structure interaction method is closer to the real installed load. Compared with the traditional method, static stress obtained by the coupling method is reduced from 248.69 MPa to 51.49 MPa, and deformation is reduced from 0.81 mm to 0.16 mm; the top six modals of the rake have increased by more than 7%, successfully avoiding the engine rotor natural frequency. The coupling design method can provide a reference for improving the existing measuring rake design capability, and it can be used in subsequent design and verification calculation of measuring rake.