Abstract: The effect of heating rate in N₂ atmosphere on the pyrolysis characteristics of chlorella after Soxhlet fat extraction was studied by thermogravimetric experiment. The rapid pyrolysis experiment in tubular furnace under N₂ atmosphere showed that at 400℃, the pyrolysis conversion rate was the highest, where the yield of biooil and the pyrolysis gas were 57.6% and 10% respectively. The pyrolysis kinetics of algal residue was analyzed and compared by equal conversion methods of FWO and KAS. The results showed that the pyrolysis curve of algal residue could be divided into three stages, where the main pyrolysis stage was 155-800℃. There were two weight loss peaks in the DTG curve of algal residue. With the increase of heating rate, TG and DTG curves shifted to the high temperature zone, and the maximum weight loss rate and residual solid mass increased. Under N₂ atmosphere, the apparent activation energy and pre-exponential factor of the main pyrolysis stage of algal residue were 228.46 kJ/mol and 2.49×10²¹ min^-1, respectively. At this stage, the pyrolysis data of algal residue was well simulated using FWO and KAS method, and the linear fitting correlation coefficient (R²) was above 0.96. The best pyrolysis function was dα/dT=2.49×10²¹/β exp(-228.46/(RT))(1-α)⁸.