With the continuous development of the national economy and the growth of energy demand, the exploitation of heavy oil reservoirs is imperative. Based on the characteristics of fractured heavy oil reservoirs which are exploited by thermal recovery, the well testing theory model of steam stimulation and steam flood considering heat loss is established, the solution of Laplace space in the condition of infinite formation is gained, and the method of numerical inversion is used to figure out the corresponding type curve, the sensitivity of parameters is analyzed.