The invention belongs to the technical field of internal combustion engines and provides a carbon deposit generation test platform for a direct-injection oil injector in an automobile engine cylinder. The carbon deposit generation test platform comprises a base, supporting columns, an oil injector mounting plate, an oil injector fastening connector, an oil injector fuel oil inlet mounting base, a jet nozzle heating component, a heat insulation layer, a temperature control component, a fuel oil supply system, an oil injection control component and the like. According to the carbon deposit generation test platform, the jet nozzle heating component and a temperature control system control the temperature of the head portion of the oil injector so as to simulate the temperature environment near the oil injector in the engine cylinder, fuel oil with certain pressure is supplied by the oil supply system, and the oil injection process is controlled through the oil injection control system. Single parameter variation can be conducted on parameters in the carbon deposit test process of the oil injector of an engine, and the influences of single variables such as the jet nozzle temperature, oil injection pressure, oil injection pulse width, oil injection frequency and the fuel oil constituents on carbon deposit are researched. The carbon deposit generation test platform is reasonable in design, simple in structure and suitable for optimization design of carbon deposit generation test platforms of oil injectors.