Anaerobic digestion of low-grade biomass has attracted increasing interest in reducing greenhouse gas emission and facilitating sustainable development of energy supply. The theory of anaerobic digestion biogas generation and feedstocks are presented in this paper. It provides a review on mathematical model of and simulation research on the conversion of C

N

P in the process of anaerobic digestion. First order kinetic model is the simplest mathematical model which can simulate the dynamics of methane production. The advanced mathematical ADM1 is most popular

and simulates the conversion of C

N

P in anaerobic digestion. The model

simulation subjects and results of anaerobic digestion biogas generation of common substrates are given. Methane yield is the main subject of simulation investigation which is studied in almost all simulation researches on anaerobic digestion biogas generation

and some research reports the variation of volatile solid

volatile fatty acid

COD

CH4

CO2 and inorganic carbonate in the process of anaerobic digestion through mathematical modeling

with which the conversion of C can be determined. Simulation researches on the conversion of N include variations of ammonia nitrogen

inorganic nitrogen and total nitrogen. Simulation research on the conversion of P from sludge digestion is also presented. The challenges and future research trends of the conversion of C

N

P in the process of anaerobic digestion are forecasted.