The evolution characteristics of the squeezing flow field in atmospheric diesel fuel were studied using high-speed squeezing flow device. Effects of four kinds of armature structures, including round hole and sector hole, on the squeezing flow characteristics in the gap between solenoid valve and armature under the high-speed condition of 29.9—67.4m/s² were simulated using Fluent software. The armature structure with ideal squeezing flow characteristics was obtained and verified by high-pressure fuel supply system. The results show that when the acceleration of the armature increases from 29.9m/s² to 67.4m/s², the maximum pressure of the fluid on the armature surface increases from 0.12MPa to 0.24MPa, the jet velocity at the armature edge, and hole edge and the vorticity at the armature side wall increase, thus the flow at the diversion hole becomes more chaotic. When the square armature is replaced by the round armature, the flow path between the gaps is short, the area of the high-pressure zone is reduced by 6.6%, and the liquid between the gaps can be discharged faster. Compared with round hole and guiding trough, the fan-shaped hole on round armature has weak influence on the jet flow in the middle of the hole, the pressure on the surface of the armature is the least, the resistance is the weakest, and the response speed is the fastest. The experimental results show that the closing delay of guiding trough and sector hole armature is 0.610ms and 0.405ms respectively at the speed of 400r/min, and the former is 50.6% longer. At the speed of 1250r/min, the closing delays of the guiding trough and the sector-hole armature are 0.850ms and 0.720ms, respectively, and the former is 18.1% longer.