SHANGHAI—China disclosed new, multiyear subsidies and other inducements to get government officials and agencies to buy energy-efficient vehicles in a boost for plug-in electric and hybrid auto makers.

Under the new rules, which will be phased in over the next two years, battery-powered cars, gasoline-electric hybrids other new non-polluting vehicles must account for no less than 30% of all new cars bought for official use each year,…