The invention provides a method for monitoring communication states of steam flooding wells and system. The method for monitoring the communication state of the steam flooding wells comprises the following steps: performing pulse well trail testing on a steam flooding well group, wherein the pulse well testing process is well testing process for performing periodic adjustment on steam injection output of a steam injection well; in the well testing process, the steam injection well is an excitement well, and a production well is an observation well; according to temperature and pressure variations of mouths of the production well and the steam injection well in the pulse well testing process, performing qualitative evaluation on communication of the steam injection well and the production well; and establishing mathematic models, achieving quantitative splitting of steam amounts of the steam injection well and corresponding production well, thereby performing quantitative evaluation upon the communication states of steam flooding, injection and production wells. By adopting the scheme of the invention, on the basis of monitoring upon conduction and diffusion of substances and energy under formation conditions, practical effects of stream to oil wells under the formation conditions can be directly reflected, and thus conclusions are direct and reliable.