Can I refuse a visa to marriage immigration?

Perhaps, one is the lack of materials (such as insufficient financial guarantee, failure to get the necessary vaccine, unqualified medical examination, etc.). ), there is also a suspicion of fake marriage. So there is nothing to worry about in a real marriage with sufficient material resources.

Success rate, you also don't say what country. Moreover, the statistics are of little significance, because there are many calculation methods (insufficient materials-if a form is accidentally omitted and is approved after being filled up, it is likely to be counted as the' refusal rate' statistics, but it was actually approved in the end), and the appeal was successful after being rejected, and so on. So you can only prepare your own materials, and don't think about it with other probabilities. Even if the success rate is 99%, it doesn't mean much to those 1%.