This has several meanings depending on who you are talking to and, most likely their age.
In the Political World, it is you are PRO BUSINESS
In today’s slang:
Stand on business meaning
Put simply, to “stand on business” means to take care of your responsibilities or put your money where your mouth is. You get done what needs to be done and follow through, similar to the term “taking care of business.”
According to Urban Dictionary, the phrase is defined as: “To take care of your business/obligations. To be about your grind,” (meaning completing tasks that need completing) or, “When faced with a situation, you are urged to handle your own affairs.”
Standing on Business
If you are “standing on business,” it means you are sticking to your values and walking the walk, not just talking the talk.
For example, someone who posts to their social media page saying they are going to become their own boss and later goes on to successfully open their own small business or become an entrepreneur would be “standing on business.” Someone who is standing strong in ending a relationship that was bad for them can also be “standing on business.”