对一台采用液压驱动可燃气喷射器的高压缩比直喷式天然气发动机进行了试验。用电热塞点燃一束燃料，使发动机在一定转速和负荷范围内稳定运转，由于在扩散燃烧期内燃烧缓慢和局部的发火不良，其热效率比燃用通常的气－油燃料时的要低。本文根据压力－时间变化关系、发动机性能和排放的测定结果，详细地讨论了点火和燃烧的改进研究。 A high compression ratio direct injection natural gas engine with hydraulically driven combustible gas injectors was tested. A glow plug is used to ignite a fuel which causes the engine to run stably over a range of speeds and loads. Its thermal efficiency is lower than with conventional gas-oil fuels due to slow combustion and localized gassing during diffusion combustion. In this paper, based on the pressure-time relationship, the engine performance and emission measurement results, the ignition and combustion improvements are discussed in detail.