In this study, a rapid compression machine (RCM) was used to study the traditional JP-5 fuel and the JP-5 surrogate. In the experiment, the ignition delay characteristics with low-to-intermediate temperature compression temperatures ranging from 675 to 800 K, compression pressures of 10, 15 and 20 bar, and equivalence ratios of 0.25 and 0.37 are discussed. Among them, the auto-ignition delay time of JP-5 and the surrogate all shorten the ignition delay time as the compression pressure and equivalence ratio increases, where the negative temperature coefficient (NTC) phenomenon begins to occur at temperatures of approximately 732–746 K. It is worth noting that an increase in pressure or the equivalence ratio of the two fuels changes their low-temperature oxidation reaction pathway, thereby increasing the initial temperature of the NTC. The two fuels showed similar ignition characteristics in the measured temperature range. The difference between the two fuels was approximately 6.18% when the equivalence ratio was 0.37, which means that the surrogate reproduced the ignition delay characteristics of the real fuel.