This paper presents a multi-GPU platform which can solve the incompressible 2D Navier-Stokes equations efficiently. We design a tile structure to distribute the whole computation domain evenly to multi-GPU, each GPU only solves the equations in a limited area but maintaining the whole computation area within its own device memory. Even though the Semi-Lagrangian method may trace the particles across different graphics cards, the memory update does not constitute the bottleneck of the whole performance. During the experiments single, double and triple GTX 260 graphics cards are installed to construct the platform with CUDA 2.3. With a triple GPUs configuration, we can achieve about 270 speedup compared to the according CPU version without including the memory copy cost, and this configuration is also about 2.1 faster than the single GPU version.