The invention discloses a double-spindle box four-cutter head eight-shaft cylinder boring machine and a control method thereof. The double-spindle box four-cutter head eight-shaft cylinder boring machine comprises a base, an upright post, a spindle box screw rod, a spindle box mounting block, a spindle motor, a motor mounting plate, spindle boxes, rough boring cutters, fine boring cutters, tooling fixture bodies and a workbench. According to the double-spindle box four-cutter head eight-shaft cylinder boring machine, the two spindle boxes are assembled, each spindle box is provided with four cutter shafts, the spindle boxes achieve transmission output through synchronous pulleys, one motor drives the four boring cutter shafts to synchronously move at the same time, and the rough boring cutters and the fine boring cutters move at the same time; the tooling fixture bodies can efficiently and stably fix workpieces in a numerical control hydraulic manner, the clamping force is adjusted during rough and fine boring, and the precision of the processed workpieces is further improved; and the utilization method is simple, the technical requirement on workers is relatively low, the production efficiency of boring can be effectively improved, and a cylinder product with relatively high precision can be obtained.