Crops in the northwest arid region of China frequently suffer from low emergence and poor yield due to high water deficit. Mulching is an important approach to reduce irrigation amount while increasing productivity but faces the challenge of ecological adaptability in this region. A field experiment was carried out in the three growing seasons from 2011 to 2013 to study the effects of mulching with crushed wheat straw padding and plastic film on sunflower seed emergence and yield under different irrigation intensities. A two-factor (mulching and irrigation intensity) completely randomized block design was applied, resulting in a total of 12 treatments repeated three times. Mulching treatments include zero mulch (N), straw mulching at the beginning of the experiment (S), plastic film mulching when sowing (F; a commonly used mulching by local farmers), and double mulching with plastic film on the crushed wheat straw layer (SF). Irrigation intensity includes high (H = 900 m³·ha⁻¹), medium (M = 750 m³·ha⁻¹), and low (L = 600 m³·ha⁻¹). Results showed that all mulching treatments promoted the early emergence of seedlings compared with N, with SF and F performing better than the rest. SF was the best-performing mulching approach in this study, and it had significantly improved sunflower yield and yield components compared with other treatments. In SF, medium irrigation level had significantly increased sunflower 100-seed weight. Therefore, SF with M irrigation level showed the most positive effect on sunflower production, and it is now the recommended agronomic solution for sunflower production in the northwest arid regions and, potentially, other irrigated areas with similar ecological conditions.