In recent years, there is very little report on the characteristics of the co-combustion between municipal sludge and biomass charcoal. Therefore, the thermal characteristics and kinetics of municipal sludge, rice husk hydrochar and their blends in the combustion process were investigated in this work. The mass percentages of rice husk hydrochar of in the blends were 10wt%, 30wt%, 50wt%, 70wt% and 90wt%, respectively. The experiments were performed via a thermogravimetric simultaneous thermal analyzer at different heating rates (10, 20 and 40℃/min) with a changing temperature ranged from room temperature to 1000℃. Meanwhile, the Flynn-Wall-Ozawa (FWO) method was used to calculate the reaction kinetic parameters during these combustion processes. The results showed that the mass of volatility, ignition and burnout index of rice husk hydrochar were all higher than those of municipal sludge and rice husk hydrochar had good combustion characteristics. As the ratio of mixed rice husk hydrochar increased, the residual mass of the mixture reduced and the ignition performance worsened, however, the combustion performance enhanced. And the correlation coefficient of the activation energy of the combustion of rice husk hydrochar, municipal sludge and their mixture were all higher than 0.95. When the ratio of rice husk hydrochar blended in municipal sludge was higher than 50wt%, the average activation energy of co-combustion was lower than the average activation energy of rice husk hydrochar burned alone, when the ratio reached 70wt%, the lowest average activation energy of 85.48 kJ/mol appeared. There was a synergistic interaction during the co-combustion process, and compared with other mixed rice husk hydrochar ratios, the co-combustion effect of samples was better when the ratio was 50wt%. The research results provided a preliminary theoretical basis for co-combustion of municipal sludge and rice husk hydrochar.