how long it takes the application for permit work with B1 visa?

I am not quite sure of the tenor of your question. A B-1 visa is for a person coming to the US for business purposes. Such entry is not for work, and you cannot apply for an employment authorization document (EAD) based upon a B-1 visa. If you enter under refugee status, you are allowed employment authorization upon being admitted to the US and having the EAD submitted and approved. The current processing time is approximately 4.5 months. If you are applying for asylum, you need to wait 150 days after the application is filed before filing an EAD application. Current processing time is approximately 30 days for initial applications according to USCIS published processing times. Due to the limitations of the Lawyers.com Forums, Alan Lee & Arthur Lee, Esqs.’ (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.