You've worked long and hard to make your business successful. Something that never happened was your spouse taking a role in that business. To them, this was your job and your work. They often mocked what you did and said it wouldn't be successful. That resentment built up, so much so that you decided to end your marriage once you saw your business was more profitable than you'd hoped for.
Now, you're outraged that your spouse is trying to obtain a portion of your business assets. Yes, California does allow for the equal division of your marital property, but will your business be included in that? Is there any way to protect it?
The good news for you is that your business might be considered to be separate property if it was started before you got married. However, keep in mind that any property acquired during your marriage is going to be considered to be marital property (in most cases). As a result, any profits you make during your marriage could be marital property and split. Similarly, closely held businesses, tools of the trade and produced items may also be considered marital property.
There is something else that you may want to consider. If you divorce in California, you will be subject to community property laws. However, if you are in one of the 41 states that recognize equitable distribution laws, then you would divide your property fairly, not equally. There are good and bad things about each kind of property division law, but it's necessary to consider the differences if you're divorcing with a business and have the option of divorcing in more than one state.
If you don't want your spouse to have your business, build up your case
If you really don't want your spouse to benefit from your business but live in California, then it's smart to start building a case to show that this is separate property. On top of that, you may want to work on negotiating with your spouse directly. You may be able to give them other assets in exchange for leaving your business and its assets to you.
Everyone's case is different, so it's a good choice to talk to your attorney as well as other industry professionals to have your business assessed and assigned a value as well as to try to negotiate to keep your spouse from accessing your assets.