Abstract: With the increase of long-distance natural gas pipelines in China, single pipeline is vulnerable to frequent accident, shutdown or other problems. Through reviewing the crossover specifications for long-distance parallel natural gas pipelines and related crossover techniques, this paper proposes four crossover schemes for the parallel X and Y Pipelines and makes equivalent contrast research on pipeline. The result shows that there is an inverse correlation between the number of crossover valves and the annual system failure reduction. With the increase of the number of crossover valves, the annual failure frequency of system increases and the redemptive lost gas volume per year decreases, which leads to a smaller ratio between the redemptive lost gas volume and the increased investment. The crossover scheme with 1 crossover valve chamber between 2 compressor stations reveals the best cost performance, which means that there are an optimum number of crossover valves under a crossover scheme. For the parallel X and Y Pipelines, a scheme of 1 valve chamber between compressor stations with both crossover pipes before and after valves is recommended. This scheme can improve the emergency allocation capability of the pipeline and guarantee the reliability of the whole system. It is economically reasonable.