Since there are two problems when using current workflow to integrate existing software services: 1) Information of the integrated service is insufficient to satisfy the service integrating needs;2) Only few node types without any business meaning can be chosen during process customization, which complicates the process customization. Thus, a new workflow model was proposed. Firstly, three information parts of the workflow model: structure information, service information and people information were determined by analyzing actual business processes under service integration environment; secondly, the corresponding description between three information parts and JPDL (JBoss jBPM Process Definition Language) was given to prove the completeness of the new workflow model; finally, the key elements of each information part were described. The experimental results show that 48 business processes can be quickly built and met the actual business needs based on 35 services. The rich service information provides guarantee for the process operation and the execution correct rate is 100%; the process customization is more convenient with less than 2 min from process customization to execution. The results show that the proposed model can help to build new business process quickly based on existing software services and save the software development costs.