To solve the problem of delay interference in the execution of a multi-robot path planning system, a k-robust safe interval path planning algorithm based on safety interval is proposed in this article. Firstly, the global time interval is introduced, and the time occupied by robots and the k-robustness factor are added together as the obstacle time interval of nodes. Then, the global time interval is updated, and the safe interval constraint of the global time interval is used to avoid conflicts between robots. Secondly, the A ∗ method with k time expansion is proposed as the core algorithm of multi-robot low-level path planning, where k is the set robust factor. This method can deal with the robust planning problem in the spatio-temporal relationship of multi-robot. Finally, all robot path planning is completed under the constraint of a global time interval. Simulation results show that the solution success rate of the proposed algorithm is 37% higher than that of the existing improved k-robust conflict-based search algorithm, and the solution time is reduced by two orders of magnitude. It provides a more efficient and robust scheme with a delay margin for multi-robot path planning, which provides a more efficient and robust scheme with delay margin for multi-robot path planning, and further verifies the effectiveness and feasibility of the proposed algorithm in real robots.