What are the conditions under which the hold-up problem occurs and what is its applicable scope? Academic views are not unified. This paper constructs a theoretical model based on outsourcing situation, deduces the conditions of hold up problem for the first time, and explains the relationship among investment distortion, under-investment and over-investment. Then, the paper probes into the economic laws behind the hold up problem, finds out the reasons for the efficiency loss of different organizational forms, and provides theoretical basis for the construction of efficient organizational forms.Finally, the paper reveals the model setting rule followed by the hold up problem in the model, explains the logical relationship between the core assumptions and conclusions of the representative model, solves the problem that empirical studies mostly focus on verifying the conclusions of the theoretical model and fail to test the logical relationship between the assumptions and conclusions, and helps to clarify the application scope of the hold up problem.