Simon Clarke targeted the shops within weeks of each other and demanded cash from the tills.
The 44-year-old fled with money from a newsagents in Johnson Road in November 2018 and then pushed a worker against the counter as he took the cash till from a sweet shop in Upper High Street the following month.
After examining CCTV footage officers were able to identify Clarke as the prime suspect and he was traced and arrested in January.
Clarke, of no fixed address, pleaded guilty to two counts of robbery and was sentenced to three years and two months at Wolverhampton Crown Court on Wednesday .
Pc Kelly Brotherton, from West Midlands Police CID, said: "This was a terrifying situation for shop staff to be faced with, they didn’t know what Clarke might do to them.
"Our enquiries established the same robber was responsible and we were able to identify it was Clarke. He is now behind bars and unable to strike again."