The scheduling of workflows is a well-known non-deterministic (NP) problem because it contains multiple targets constraints.This paper proposed a time-quality optimization scheduling algorithm by layering the workflow model into three layers

such as mapping layer

dominant layer

and decision layer

respectively.The algorithm has two stages

stage one is called detection

it can improve the production quality by means of cycle machining in this stage;another stage is virtualization

which uses iterative way to virtualize nodes in mutual constraints into a new virtual node

abstracts the services

and simplifies the selection of services eventually.In comparison

the proposed algorithm was more effective than the traditional minimum critical path algorithm in the same experimental environment.