The invention discloses a dirty oil and sewage separation device. The device comprises a liquid storage container and an oil and water separation mechanism, and the oil and water separation mechanismis provided with a high-position throttling baffle plate and a low-position throttling baffle plate; the liquid storage container is partitioned into a dirty oil cavity and a sewage cavity by the high-position throttling baffle plate, and the bottom of the high-position throttling baffle plate is provided with a communicating hole communicating the dirty oil cavity with the sewage cavity; the bottom of the low-position throttling baffle plate is provided with a valve; a transition groove is formed between the low-position throttling baffle plate and the high-position throttling baffle plate; dirty oil and sewage flow from the dirty oil cavity, the dirty oil is blocked in the dirty oil cavity by the high-position throttling baffle plate, and the sewage flows into the transition groove through the communicating hole; the sewage in the transition groove flows into the sewage cavity through the valve or/and flows above the low-position throttling baffle plate into the sewage cavity. The problem that for existing well repairing and operation sites, the dirty oil and the sewage cannot be processed is solved.