The laboratory calender is composed of calender and traction coiler. The number of calendering rollers can be divided into two rollers, three rollers, four rollers and five rollers. The arrangement of calendering rollers can be divided into I-shaped, L-shaped and S-shaped rollers. The calendering rollers are heated by oil with high heating speed and high temperature control precision. The oil circuit of calendering rollers can be changed rapidly between different connection modes of series, parallel and mixed connection. The clearance of calendering rollers can be adjusted directly by driving clearance indicator, and each calendering roll is independent. Vertical servo drive can realize stepless adjustment of speed difference between two adjacent rolls and measurement of rolling torque of arbitrary calendering rolls according to need. It can also be equipped with visual system to realize the development of raw material dispersibility and the detection of gel spots, fish eyes, black spots and other thin film quality defects.