A video shared on social media showed an officer striking a man who was being restrained on the floor of a bus in Seaside on the evening of July 16.
Sussex Police have now concluded 'the officer's actions were reasonable and proportionate to the risk posed at the moment in time, and no misconduct proceedings will be brought'.
A Sussex Police spokesperson said officers were called because the man was ‘being abusive to other passengers and refusing to leave’.
They said the man was arrested and appeared before magistrates on Monday, July 18, charged with assaulting an emergency worker and using threatening or abusive behaviour.
He was released on conditional court bail to next appear before the court on August 15, they added.
The spokesperson said: "Footage of a small part of the incident on the bus on July 16 was shared on social media whilst officers were attempting to detain and handcuff a man.
"The video has been reviewed by the force Professional Standards Department, along with CCTV from the bus of the entire incident, the officers' body-worn video footage covering their interactions with the man, witness statements and a mandatory use of force form submitted by the officer, and other information leading to the arrest.
"We strive to learn from every interaction and have shared this incident with our Independent Advisory Group (who are independent members from the local community) to better understand public perception of use of force techniques.”
Superintendent Till Sanderson, from East Sussex Division, said: "We understand the public’s concern about the video on social media but such videos rarely provide a full and accurate picture of the event, or series of events, leading to the arrest.
"Police officers are highly trained in the use of force techniques and aware that any use of force used must be proportionate and reasonable, and that their actions will be scrutinised and they will be held accountable where appropriate."