from florida my husband was 24 at the time of the accident and only worked 3or 4 yrs and ssi/disability stated he is only entitled to 300$ a month if i am working what can i do
Not sure what you are asking. It sounds like you would like to see him get more money per month.
First, it is important to know if your husband is receiving SSDI or SSI or both. You stated SSI/Disability, but I am not sure you are correctly referring to the right program. As young as he is, he could potentially qualify for SSDI with only three of four years of work under special insured status. But the amount of SSDI is totally dependent upon the amount of money he made and paid taxes on before he stopped working. That is unchangeable.
If he is receiving SSI, the only way that it can be increased is if you earn less money than you are currently receiving. I don't think that is what you are looking for.
He should contact his local Social Security office and ask them the questions. They have access to all the records. It is possible that he is receiving as much money as he can possibly get from SSA. However, it is also paossible that this money will be paid the rest of this life if he is disabled the rest of his life.
If he might be able to return to work someday, he needs to understand the work incentive rules that are quite complex, but are designed to help him get back into the work force and off of disability benefits. But that might not be feasible for him.