Laser cladding (LC) exhibits great potential in reinforcing soil-engaging parts of tillage machinery. However, for typical soil-engaging parts with complex curved surfaces like the rotary tiller blade, it is imperative to address discontinuity and residual stress of the coatings-key issues caused by improper cladding paths and curvature-induced uneven distribution of laser energy, which limit the performance of LC coatings. In the presented study, Ni60-diamond composite coatings were fabricated on the rotary tiller blades with complex curved surface by LC. Based on the relationship between LC parameters, microstructures and properties, the Ni60-diamond composite coating with good LC formability, non-graphitization of diamond, strong abrasive retention force and high wear resistance were obtained by the LC parameters of P = 1000 W, v = 10 mm/s. Then, by establishing the high-precision model (error of 0.382 mm) of rotary tiller blade, three cladding paths were designed as 0°, 45° and 90° along the blade edge direction, and the optimized composite coatings were prepared according to the cladding path on the rotary tiller blades. Through simulation and experiments, with the increasing curvature, the residual stress of the coating increased due to the uneven spatial distribution of thermal stress in the laser spot. The residual stress of the coating reached 68.8 MPa at the maximum curvature of 1/25 mm −1, exhibiting through-cracks across the coating. On the other hand, with the increase of number of laser-scanning passes, the residual stress of 45°-and 90°-path coatings increased significantly under the effect of heat accumulation, 25–35 % more than the 0°-path coating. This study not only provides technical basis for preparing wear-resistant coatings on soil-engaging parts, but also proposes a strategy for the reinforcing, repairing and remanufacturing of the complex parts by LC.