The reasonable functional modules partition is crucial to technical solution of function in product innovation design. Technical evolution factors are not considered in current product module partition method. The correlation of customer demand and product function unit, function unit flow correlation and function technology correlation are synthesized for function module partition in product innovation design. Based on function base expression, function chain and function structure is established to provide basis of function correlation analysis. Function correlation matrix is established by combining the correlation matrix of customer demand and product function unit, the function unit flow correlation matrix and function technology correlation matrix. The dynamic cluster analysis of fuzzy equivalence matrix is used to form function module. The function module partitions are evaluated by polymerization degree and coupling degree. The presented dynamic module partition method has strong distinguishing ability.