Abstract: The entity models with different structural parameters is established by using Pro/E using multistart spiral pipe as the research object and water as heat transfer medium.The heat transfer process of spiralpipe is simulated through the FLOTRAN CFD in ANSYS.Orthogonal experiment is performed to study theeffect of the main structural parameters on the heat transfer enhancement process.The comprehensive evaluation index (PEC-1) of heat transfer performance improves significantly with increasing coil head number.PEC-1 value decreases sharply with helix angle at forty-five degrees or larger.The groove depth has relativelysmall effect on the value of PEC-1.The structural parameters of the multi-start spiral pipe is optimized byanalyzing the variances of orthogonal experiment results.