About 100 police officers and staff from five forces will lead Brighton's Pride parade on Saturday.
Wonder Woman impersonators took part in a previous march
Sussex Deputy Chief Constable Geoff Williams and Surrey Chief Constable Bob Quick will join staff from Sussex, Surrey, Hampshire, Gwent and the Met.
It is the fourth year police have marched with the parade - the centrepiece of the event, which attracts 120,000 visitors to the city.
Road closures and diversions and bus service alterations will be in place.
The parade, the theme of which this year is musicals, begins at Madeira Drive at 1130 BST.
It finishes at Preston Park two hours later, where the main celebrations take place.
Roads along the route will remain closed until pedestrian numbers reach a safe level to allow traffic to move again.
Chief Supt Paul Pearce said the Pride weekend, the city's biggest operational policing commitment, puts considerable strain on police resources.
"The policing of Pride involves an enormous amount of preparation, planning, consultation and enthusiasm," he said.
Police will be using an Ion Track drug testing machine and sniffer dogs to deter dealers from targeting the event.
But random drugs tests will not take place, and people in the park would only be searched where there was specific intelligence to identify individuals suspected of drug activity.
Mr Pearce said officers would also be on the lookout for pickpockets and bag thieves.
"Unfortunately thieves see Pride as an ideal opportunity for stealing your most valuable things," he said.
"Operating in crowds and in busy dance tents, bars and clubs they will be watching for unattended handbags, rucksacks and anything else that might contain purses, wallets, phones or iPods."