The diamondback moth (Plutella xylostella) is a worldwide devastating pest specialized on Brassicaceae plants, including three main vegetables of China i.e., cabbage, Chinese cabbage, and radish. To develop a cost-effective control program, we compared the adult oviposition preference and life table parameters of P. xylostella on these three crops. In the no-choice and choice oviposition tests, P. xylostella females laid more eggs on Chinese cabbage than radish and cabbage. In addition, P. xylostella larvae consumed more leaves when feeding on Chinese cabbage compared with other plants. The age-stage two-sex life table indicated that the intrinsic rate of increase (r) of P. xylostella was higher on Chinese cabbage (0.233 d⁻¹) than radish (0.203 d⁻¹), and cabbage (0.135 d⁻¹). The fecundity was the highest on Chinese cabbage, while developmental duration from egg to adult on Chinese cabbage was significantly shorter. Chinese cabbage leaves exhibited lower activities of defensive enzymes and significantly higher total protein content, which may account for the higher preference and performance of P. xylostella on Chinese cabbage. These results suggest that Chinese cabbage is highly susceptible to P. xylostella and needs more frequent monitoring and control strategies against this pest, although field trials are needed to confirm these findings.