The utilization of water resources and water security in Central Asia are critical to the stability of the region. This paper assesses the water security of the five Central Asian countries (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan) by using the projection pursuit model based on particle swarm optimization (PSO-PEE). The results show that the average annual water consumption in Central Asia is about 1255.57 x 10(8) m(3), and the proportion of agricultural water consumption decreased due in large part to the changes of crop planting structure. For the ecological security, Kazakhstan, Tajikistan and Kyrgyzstan have improved their status, but Turkmenistan is getting worse. For the quantity security of water resources, Tajikistan and Kyrgyzstan are relatively safe, whereas Uzbekistan is at risk. For the socio-economic conditions, Kazakhstan scored the highest, while Tajikistan and Uzbekistan scored the lowest, water consumption per 10,000 dollars of GDP across all five countries is relatively high but shows a significant decreasing trend. For the water supply and demand security, the status of Kazakhstan, Kyrgyzstan and Tajikistan are better than that of Turkmenistan and Uzbekistan. Kazakhstan has achieved a relatively safe level (level II) and the degree of water security is high. Kyrgyzstan, Tajikistan and Turkmenistan are only in the basically safe level (level III). Uzbekistan is under significant pressure with regard to water security (level IV), which indicates that the country needs to strictly control population growth and strengthen the comprehensive management of water resources.