Symbolic execution is of vital importance for software engineering activities

such as path exploration

debugging and verification.However

symbolic execution techniques do not scale well for complicated realistic programs

because the number of feasible executions paths increases exponentially.Path condition expression extracting and constraint solving are the bottlenecks of symbolic execution.State merging is a common method to tackle the problem of state explosion

but this abstract procedure would be prone to incorrect path information.According to different searching strategy of symbolic engine

symbolic execution tools could generate unsolved path conditions during the process of symbolic variable state combination.A symbol value analysis based on dependent condition reconstruction method is proposed

which analysize the logic path conditions and extracts the common variable symbols to enhance the combination efficiency.Meanwhile

the backward analysis method is used to generate dependent condition set to improve the accuracy of path analysis.The experimental results demonstrate that it has better execution efficiency and accuracy compare to the tradition state combination methods.