1, fixed and volatile evidence of an affair For the contents of mobile phone messages, e-mails, computer blog diaries and qq chat records between a married party and the object of an affair, if possible, the public security department should be entrusted to handle such evidence in a fixed way. If conditions do not allow, you should try to save it yourself. Mobile phone messages can be photographed with a digital camera together with your mobile phone, and computer and network materials can be intercepted and saved in full screen. 2. Collect written evidence. Written materials in the form of "confession", "confession", "guarantee" and "agreement" written by one of the parties to the marriage at the early stage of the sudden exposure of the affair, due to feelings, urgency or repentance; Transcripts of police intervention in dealing with acts such as whoring, staying with prostitutes, opening a room for dating, illegal cohabitation, etc. by one party to the marriage; The handling decision documents and materials that the employer may have when it finds out that one party to the marriage is whoring or having an affair; Documentary materials written by the insider or witness about marital affair or illegal cohabitation. 3. Collect audio-visual evidence. The recorded data of the negotiation between husband and wife about the marital affair mainly depends on the parties themselves. It is safer and more reliable and has independent evidence effect to entrust a third party's investigation company, the private detective, to collect the video and photos of the behavior of one party and a third party in public places, such as double entry, hand in hand hug or entering and leaving the room. As long as it is not illegal, the audio-visual materials shot and recorded by the parties or their agents can be used as evidence and have probative force. 4. Collect on-the-spot evidence. Collect on-the-spot evidence of catching a rape in bed. It is better to shoot a video to explain the problem. It is very difficult to collect this kind of evidence, and it is also easy to cause fierce real conflicts; Courts usually don't advocate this kind of evidence, and the judicial circles have great disputes about the collection methods of this kind of evidence. Article 1079 of the Civil Code of the People's Republic of China * * * If one of the spouses requests a divorce, the relevant organization may mediate or directly file a divorce lawsuit with the people's court. When trying divorce cases, the people's court shall conduct mediation; If the relationship has indeed broken down and mediation fails, divorce shall be granted. Divorce shall be granted if mediation fails under any of the following circumstances: (1) bigamy or cohabitation with others; (2) committing domestic violence or abusing or abandoning family members; (three) gambling, drug abuse and other bad habits; (four) separated for two years due to emotional disharmony; (five) other circumstances that lead to the breakdown of marital relationship. If one party is declared missing and the other party files a divorce lawsuit, the divorce shall be granted. After the people's court has ruled that divorce is not allowed, and the two parties have separated for one year, if one party files a divorce lawsuit again, divorce shall be granted.