To address the challenges of observing colorless and transparent samples with traditional microscopy techniques, a phase microscopy imaging system based on the Transport of Intensity Equation was designed. This system utilizes the axial differential approximation method and the in-focus image approximation method, combined with a binocular CMOS camera to simultaneously collect overfocused and underfocused images, thereby solving the Transport of Intensity Equation and achieving phase retrieval of the sample. The system also integrates an autofocus algorithm and a phase-related field of view correction algorithm to reduce the impact of human and equipment errors. Tests have shown that the system achieves a resolution of 2.19 μm under a 10 objective lens. In practical applications, it has not only successfully performed phase retrieval on human blood smears, observing the unique structure of red blood cells, but it can also be used for scratch detection in petri dishes. Due to its low cost, ease of implementation, and broad application potential, the system demonstrates significant advantages in observing colorless and transparent samples.