Whether continuous ridge–furrow plastic film mulch (PM) and flat planting with PM is sustainable for soil water status and yield remain unknown. The study investigated effects of ridge–furrow PM applied in spring (RFMS) or autumn (RFMA), flat planting with no mulch (CK), flat planting with 60% mulch in spring (MS) or autumn (MA) on soil water and maize yield from 2016 to 2019. High yields in RFMA resulted from high soil water storage (SWS) consumption in 0–220 cm soil layer during the growing season, with main water supply for early plant growth coming from 0 to 80 cm layer and can be recovered from rainfall during later in the growing season. From 80 to 220 cm, SWS declined during growing season but recovered during next fallow season. The 2016 growing season had the lowest precipitation, and RFMA and MA had significantly more deep soil water consumption, which was replenished to normal levels in the following fallow season of 2016–2017. After four growing seasons, all PM treatments did not reduce deep soil water, compared to CK, or follow a declining trend over time, i.e., continuous cultivation with PM on Loess Plateau did not reduce soil water status.