A pulverized coal gasification device and process for producing high heating value coal gas with low carbon residue content includes a U-shaped coal gas generation furnace and a coal gas-semicoke separating device, and the U-shaped coal gas generation furnace consists of two section structures including high-temperature and low-temperature sections which are arranged in a U-shaped manner; the high-temperature section and the low-temperature section share an ash hopper; the high-temperature section is a downward entrained-flow bed, and the low-temperature section is an upward entrained-flow bed; and an inlet of the coal gas separating device is connected to the outlet of the low-temperature section, a solid outlet of the coal gas separating device is connected to an inlet of the high-temperature section, and a gas outlet of the coal gas separating device is connected to a coal gas waste heat utilizing and purifying system. The coal utilization rate can be greatly increased.