Solvers’ participation is essential for successful implementation of crowdsourcing contests for problem solving (CCPS). Many efforts have been made to investigate solvers’ various participation behaviours in CCPS. Whether or not a solver will conduct a behaviour is the result of decision making. However, to our knowledge, few studies concentrated on solvers’ participation from a decision process perspective and little is known about the factors that influence the decisions that solvers are likely to make. This study aims to develop a framework for demonstrating solvers’ decisions and their relations, thereafter identify the factors that affect each of decision makings. It does so through the qualitative structured interviews conducted with solvers in a crowdsourcing platform. The interviews capture four major interrelated solvers’ decisions that are decisions of participation in CCPS, platform selection, contest selection and determination of effort level, respectively. Moreover, the factors including solvers’ motives, solvers’ individual characteristics and incentives, and their roles in each of solvers’ decision makings are presented. The findings improve the understanding of solvers’ participation in CCPS from a decision process perspective. With the further comprehending of factors that affect solvers’ decision makings, this study provides practical implications for crowdsourcing platforms to improve their services for solvers.