Water strider can stay and move quickly on water surface by surface tension. Water strider robot inspired by such small aquatic insect would have a wide variety of applications in military reconnaissance, environmental monitoring, and pipeline inspection. However load capacity of the robot is a big challenge for its practicality. Under this situation research on load capacity of water strider robot is developed in this paper. Shape function of meniscus surrounding an elliptic cylinder is established and the forces exerted on leg by water are calculated. How contact angle and dimension of the supporting leg influence its load capacity is discussed. Experiments are done on robots with different surface treatment leg to test the static load capacity.