With the rapid and deep development of space exploration,the existing Earth-based navigation solutions will not be able to meet the increasing precision demand of future spacecraft navigation.Pulsar are rapidly rotating neutron stars that generate pulsed electromagnetic radiation,which provides feasibility of precisely determining spacecraft time and position using X-ray pulsar.A detailed analysis in formation and radiation mechanism of X-ray pulsars is presented.The characteristics of the exiting Earth-based navigation systems,as well as its limitations in deep space exploration,are analyzed,and then the principle of the autonomous celestial-based systems using X-ray pulsar is introduced.This paper gives an overview on the development of pulsar-based navigation and its key technologies including X-ray detector,and gives a preliminary discussion on the radio pulsar navigation.