The invention relates to a 3D printer with high accuracy. The 3D printer comprises a shell body, supporting columns, sliding blocks, rotating assemblies, connecting rods, a PLC and a balancing assembly. Each sliding block is further provided with a first motor and a first round gear. Each rotating assembly comprises a second round gear, a bearing, a supporting rod, a second motor and a third round gear. The balance assembly comprises third motors, a fixed block, lead screws, an adjusting block, a spraying head and a balance unit. The balance unit comprises a pulling rope, a sphere, limiting blocks, springs, a touch block and touch pieces. The 3D printer with the high accuracy is ingenious in design and high in feasibility, the height of the spraying head can be adjusted through sliding of the sliding blocks, the printing range of the spraying head can be enlarged through the rotating assemblies and the accuracy is high, and the spraying head can keep the vertical state all the time through the balance assembly, so that the printing accuracy is guaranteed, and the printing quality is improved.