The exploration and development of tight sandstone and gravel oil and gas reservoirs in the Huanma Lake area of Xinjiang oilfield has attracted widespread attention. In response to the low recovery rate of elastic development and production in tight oil reservoirs with volume fracturing horizontal wells, field trials of CO2 injection were conducted. Using the increase in oil production as the evaluation basis, combined with horizontal well data, optimization of parameters such as timing, injection method, injection volume, and injection rate for CO2 injection was carried out, and MaHW001 well was selected for field trials. The study showed that injecting 3403 t of carbon dioxide into the well could increase oil production by 16.1 t per day, with significant effects. Optimization of CO2 injection and production parameters revealed that the optimal parameter combination was “CO2 + water displacement plug” combination, with an injection rate of 120–160 t/d, injection pressure within 15 MPa, and well shut-in for 60–80 days. The results of this field trial are of great significance for further improving the recovery rate of tight oil reservoirs by deepening the optimization of CO2 injection parameters.