Complex business scheduling depends on the completion of the time and accuracy and other attributes，the pursuit of a single goal cannot guarantee the balance of the aspects. Traditional algorithms often take the least time or the best quality as goal，it leads to the low quality low or the more time taken to complete the product. Aiming at this drawback，the SＲA of the exact rate with string reduction optimization under the constraint time proposed，and obtains the active interval by the constraint task. Finally，in the typical case，the traditional one-way target algorithm and the string reduction algorithm are used to solve the corresponding path respectively， and analyzed the other parameters that affect the performance of SＲA. The research shows that this algorithm has the advantages of simple，efficient and convenient implementation.