Overshooting during trocar insertion may injury patient viscera and arteries or even lead to death. It has been extensively cited as a kind of common medical negligence. Hence, this paper investigated the force characteristics during a trocar inserted into the abdominal wall and developed strategies for effective stopping upon the trocar penetrated out of the abdominal wall. First, an experimental platform with two degrees of freedom was assembled. Second, two insertion methods were compared and the insertion forces using three types of trocars were measured respectively. Subsequently, we interpreted the force characteristics in terms of insertion principle and the abdominal structure. And based on the force characteristics, we generated two algorithms for the two insertion methods, which can be utilized to stop inserting effectively upon the trocar penetrated out of the abdominal wall. Finally, we evaluated the merits and demerits of the two algorithms. This paper proposed the interpretation of force characteristics during trocar insertion and achieved effective stopping to avoid overshooting. It provides foundations for the development of automatic trocar insertion device in the future.