Can anyone answer?
If the husband doesn't want to go on first interview,what can I do?

Is he the US citizen, and you are not?
Then you should contact them as soon as you can about it. Why won't he go? They are going to want to know, from him. They will be looking for signs that this is a marriage of convenience, to get into the country. You may need a lawyer.

Why won't he go to the interview with you?

If your marriage is a bona fide marriage and not fraudulent, this may be evidence of emotional abuse and may help with a VAWA claim. If so, and if you have other evidence of such abuse, or physical, mental or sexual abuse, you should contact an immigration attorney that is experienced with VAWA petitions. The attorney will have you meet with a psychiatrist, psychologist or counselor to have them prepare an assessment as to your level of abuse to be included in the I-360 petition. This type of case is "self-petitioning" and you will not need your husbands cooperation. Privacy laws are built into the law and the USCIS will not contact your husband. All cases are filed with a specially trained unit at the Vermont Service Center (VSC).

If your marriage is not bona fide, you should withdraw your I-485 petition.