The Great Pacific Garbage Patch which characterized by exceptionally high concentrations of suspended plastic, chemical sludge, and other debris, has a variety of severe influence on the marine life and human beings. Therefore, cleaning up the patch immediately is a matter of great urgency. To solve the problem, three models which are based on different differential equations to predict the amount of waste plastic poured into the ocean are established. According to the basic model, in about next 20 years, the Pacific Ocean will be unable to hold more garbage. Based on the fact that salvaging the waste plastic in the ocean contributes to controlling marine pollution, in accordance with the better model, the Pacific Ocean still has the ability to accommodate garbage before 2060. By improving the better model, a series of results are obtained. Around 2060, the area of the Pacific Ocean Garbage Patch will reach relatively steady state; meanwhile, the annual emissions of the plastic will reach 32,397,273.47 tons. To keep a relatively stable state the area which should be cleaned up will reach about 3,601,672 square kilometers per year. To compare the effect of government increasing taxation and plastic salvaging, a conclusion is reached that the huge economic losses caused by taxes are far more than the amount of money spent in salvaging the plastic garbage.