The 301 new pieces of kit will capture evidence of crimes as they happen.
An outlay of Â£163,000 follows the purchase of 120 body-worn video devices last year, the first to be used in the force area.
Police and crime commissioner Arfon Jones said they would help to secure more convictions, especially in domestic violence cases.
The new kit will be worn by specialist officers, including members of firearms teams.
Mr Jones said the chance of prosecution in domestic violence cases rises from 72% to 81% if there is body-worn video footage for the jury to watch.
He said the cameras are "good for everybody except for the criminals" and would ensure victims do not have to go to court to give evidence.
All frontline police officers in north Wales are set to wear body camera equipment while on duty.