Photonic crystal fibers （PCFs） use periodic air hole structures to achieve light conduction， which is insensitive to space radiation. However， problems of high splice loss and low splice strength occur when the PCF splices with a PMF in the aerospace field. Therefore， investigating the fusion splicing between the PCF and PMF is crucial. First， the mechanism of splice loss between the PCF and PMF is analyzed. Next， the relationships of the splice loss with splice power and splicing time are derived via finite element simulation. The results are verified through splicing tests. Based on these， the effects of splice power and splice time on the tensile strength of splicing is emphasized， and the optimal splice power and splice time are obtained experimentally. Finally， the splicing quality is further improved by enhancing the quality of the fiber ends， shifting the heating position， multiple heating， and optimizing the splice parameters. The splicing experimental results show that the average splice loss reaches 0.82 dB， both lower than 1 dB， and the average mechanical strength is 139 kpsi， both higher than 100 kpsi. These values satisfy the requirements for low loss and high reliability of fiber fusion splicing in space applications.