I'm afraid the key to participating in the mathematical model competition is not mathematical knowledge. You must know more about some mathematical models that others have made, and then make one or two models yourself seriously, and you will certainly make great progress. Mathematical modeling is like doing an application problem at ordinary times, but it is different. When doing an application problem, conditions will be given in the general problem, all conditions will be used, and there are correct answers. Mathematical modeling needs to find its own conditions, ignoring some minor ones among many conditions, which is different from what we usually do. What's more, it has no correct answer, which needs to be tested in practice, that is, the model has no right or wrong, only good and bad. The models in the model contest are judged by the expert group. Generally, every school will give some training to the contestants who take part in the model contest. Students who have not been trained for the first time are unlikely to get good grades, because it is very different from the usual learning taste. I have a good book at hand and I want to introduce it to you. General university libraries should have them. Mathematical Model, edited by Jiang Qiyuan, published by Higher Education Press.