An inexpensive stereolithography (SL) system with high power UV-LED curing light source, the LED-SL, is developed. The working principle of the UV-LED light based SL system (LED-SL) and its characteristics are discussed. The divergent UV light emitted from the LED is focused on the resin surface by a set of focusing lens. Controlled by the computer, the workbench drives the scanner to move along X-Y plane, and polymerizes the liquid resin according to the current cross-section of a layered part. The advantages of UV-LED light source are analyzed. Because of the kinematic behavior of the mechanical scanning workbench, the exposure at the ends of a single cured line is much greater than that in the middle segment, and hence bone-shaped errors would occur, which means that the ends of a cured line have larger sizes than the middle segment. The power matching scanning method is used to improve the accuracy of a cured line, dynamically adjusting the beam power to ensure that the power is proportional to the scanning speed. The experimental results indicate that the power matching method can effectively improve the building accuracy. The SL energy consumption of UV-LED, laser and UV lamp sources are experimentally compared, and the results show that the energy consumption of UV-LED is merely 0.86% of laser and 0.1% of UV lamp, an outstanding energy conservation performance of the LED-SL.