Through the simulation experiment method, the flame spread characteristics over wood surface in concurrent flow conditions are studied. The flame spread behavior of the wood surface is observed and recorded continuously by using the techniques of flame structure displaying. Then, the flame spread process of the wood surface is inspected and analyzed based on the techniques of the temperature tracing; the flame spread controlling mechanisms of wood pieces in concurrent flow are also analysed. Meanwhile, the temperature and spread rate are obtained of fire propagation of different wood piece surfaces and in different flow conditions, which can be used for build flame spread model.