This study was conducted in an old plastic film mulching field to promote the reusing techniques of plastic film mulch in the Hetao Irrigation District, with oil sunflower cultivation in open field as the control. In soil ice crust and soil moisture recovering periods and before oil sunflower sowing and seedling periods, soil moisture and soil salt in 0-100 cm soil layer were measured within old plastic film belts, near old plastic films and between old plastic films, respectively. Moreover, emergence and seedling growth of oil sunflower were measured within old plastic film belts and between old plastic films, respectively. Results showed that reuse of the plastic film mulch increased topsoil moisture in old plastic film mulching field, decreased topsoil salt within old plastic film belts, but increased topsoil salt near and between old plastic films. Reuse of the plastic film mulch had no significant effect on deep soil moisture and soil salt. Reuse of the plastic film mulch shortened oil sunflower emergence time, increased oil sunflower emergence rate and survival rate, promoted oil sunflower seedling growth within old plastic film belts, but extended oil sunflower emergence time, decreased oil sunflower emergence rate and survival rate, inhibited oil sunflower seedling growth between old plastic films. In cultivation of oil sunflower with the reusing technique of plastic film mulch, oil sunflower should be sowed in the soil within old plastic film belts, but should not be sowed in the soil between old plastic films.