The flight capacity of Chrysomya megacephala was surveyed through flight mill and diffusion in plastic chamber. The results showed that the mean accumulated flight distances, the highest velocity and the mean flight time were not significantly different between females and males. The mean flight distance was highest at 25℃, about 4.478 3 km. When the temperature increased from 25℃, the mean flight distance would decrease. The mean flight time was longest at 20℃, about 1.226 2 h. The highest velocity was at 25℃, about 1.2210 m/s. The mean flight distances in relative humidity 50%, 60%, 70% and 80% were 5.747 5 km, 0.791 3 km, 0.385 0 km and 0.757 5 km, respectively. The mean flight time was longest at 50%RH, about 2.7868 h, and the highest velocity was 2.079 2 m/s at 80%RH. The adults of Ch. megacephala released in plastic chamber (30 m×5 m×2 m) diffused in the fan_shaped, and the highest speed was about 0.3 m/s.  The average diffusion time from one end to another was (2.52±0.63) min, with the longest about 3.08 min.