Apply for resident visa. They will issue Visit visa for a fees of 200 QAR after your wife arrives here go for medical test and finger printing and after that your wife will get resident visa. She can enter and exit as many times she want if she has resident permit.

Documents required -

NOC letter from your company.
Bank Statement 3 mnths.
Labour contract copy.
Your ID & Passport Copy.
Wife Passport Copy.
Marriage Certificate attested by External affairs from your country.
Application form filled in arabic.

Submit these documents to Labour department after you get approval from labour go to Immigration departmant for VISA.