Abstract: Decisions are often made in complex environment without exact information in many real-world occasions. Hence the capability of making proper decisions is expected for artificial intelligence agents. As abstractions of the real world, games provoke interests of researchers with the benefits of well-defined game structure and the facility to evaluate various algorithms. Among these games, GuanDan poker games are typical games with large action space and huge information set size, which exacerbates the problem and increases the difficulty to solve these games. In this work, we propose a novel soft deep Monte Carlo(SDMC) method to overcome the above-mentioned difficulties. By considering how the expert strategy acts in the training process, SDMC can better utilize the expert knowledge and accelerate the convergence of training process. Meanwhile, SDMC applies an action sample strategy in real time playing to confuse the opponents and prohibits the potentional exploitation of them, which could also lead to significant improvement of the performance against different agents. SDMC agent was the champion of the 2^nd Chinese Artificial Intelligence Game Algorithm competition. Comprehensive experiments that evaluate the training time and final performance are conducted in this work, showing superior performance of SDMC against other agents such as the champion of 1^st competition.