Abstract: Little detailed information is available on characteristics and drying quality using microwave drying on carrot. Through the tests on dehydrating characteristics and microwave drying power for carrot slice, the characteristics of the dehydration of carrot slice by microwave drying were obtained. By using orthogonal regression test on the effects of three factors (power of load, thickness of the sample slice and tempered-time) on four indexes(power consumption, dehydrating rate, the ability of absorbing moisture and quality), the regressive equations of various indexes were obtained, significance of test parameter difference was analyzed. Through nonlinear programming, the parameters were optimized, and the better combinations of parameters of power, slice thickness and tempered time were obtained. By lower-dimension, the effects of various factors on quality, rehydration rate, dehydration rate per unit time and specific power consumption were analyzed. The research results provide references for carrot producers.