“…In order to study the sustainable development of Shenzhen from the perspective of system and dynamics, a system dynamics model was established to analyze the sustainable development of Shenzhen. Among them, the level variables mainly include the total population, total water resources, current emission level of pollutants, GDP of industrial output value, urban-rural income ratio, the proportion of environmental protection investment in GDP, the proportion of R&D in CDP, the proportion of scientific and technological investment in GDP, and the number of patents applied by local residents every year, the rate variables mainly include birth rate, death rate, pollution emission coefficient of ten thousand yuan industrial output value, pollution treatment rate, ten thousand yuan GDP energy consumption, per capita income growth rate, environmental protection investment growth rate, scientific research investment growth rate, etc., the system dynamics model of society, economy and environment is shown in the following Figure 5: The average population density shall not be higher than 2300 people km2, the forest coverage shall be at least 49%, and the concentration of TSP shall not be higher than 85mg/m ', the per capita income should be at least 4000 yuan, the per capita GDP should not be less than 5100 dollars, and the environmental protection investment should account for more than 2% of GDP, the Gini coefficient is less than 30, the proportion of R&D in GDP is not less than 3.5%, the energy consumption of 10000 yuan GDP is not more than 0.4 tons of standard coal/10000 yuan, and the urban-rural income ratio is not more than 1.05 [7][8]. As shown in Equation ( 3) and (4)(5)(6):…”