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To improve the grain yield (GY) and water–nitrogen (N) use efficiency of summer maize, a 2–year field experiment was conducted using micro–sprinkling irrigation water–fertilizer integration. Surface irrigation and N application methods were applied in the control (CK, irrigation at sowing; 300 kg N ha−1). Under water–fertilizer integration, N was applied at five rates (0, 120, 180, 240, and 300 kg N ha−1, N applied at sowing, jointing, and tasseling and ratio of 1:1:1; designated WN0, WN120, WN180, WN240, and WN300, respectively). The leaf area index and dry matter accumulation increased with increasing N application rate, with a slower rate of increase when N application rate ≥180 kg N ha−1. Compared with CK, the GY of WN300, WN240, WN180, and WN120 was not significantly different,but WN120 significantly decreased by 7.16% and 5.47% than WN240 and WN300.The evapotranspiration,irrigation amount,and N application rate in WN180 were 9.86%–16.40%, 47.11%–52.23%, and 40% lower,respectively,than in CK,while the water use efficiency and N partial factor productivity was 3.38%–15.14% and 32.04%–60.43% higher.Thus,application of 180 kg N ha−1 with water–fertilizer integration can achieve high GY and improve resource–use efficiency. [ABSTRACT FROM AUTHOR]