A court heard Andrew Wishart took out the weapon and used it to terrify his partner after a binge drinking session.
Leeds Crown Court heard Wishart drank two bottles of wine on the afternoon of December 31 at the home he shared with the victim.
Philip Adams, prosecuting, said the woman asked him not to drink anymore alcohol but then went to bed when Wishart started drinking a third bottle.
Wishart went to bed later that night and his partner got up and went downstairs.
Mr Adams said Wishart began “having a conversion with himself” before going downstairs and taking the samurai sword off a wall mounting and removing it from its sheath.
The prosecutor said: “She was terrified and tried to get out of the house through the front door.
Wishart used the sword to stop her opening the door then forced her back into the property.
The point of the blade went through her jacket and caused a cut to her arm.
Wishart then took out two knives and pressed them to the top of her head.
The woman managed to run a bedroom and used her mobile phone to contact police.
She then ran downstairs and climbed out of a kitchen window.
Two officers arrived at the house in Ossett, Wakefield,
Firearms officers were called after Wisheart continued to point the weapon.
He was eventually arrested without a struggle.
Wishart, of Holme Way, Ossett, pleaded guilty to affray.
Mr Adams said the woman had provided a victim statement describing how she did not want Wishart to go to prison as he needed help to control his drinking.
He was given a 12 month prison sentence, suspended for two years. He was ordered to take part in a programme designed to address his drinking and offending behaviour.
Recorder Rachim Singh said: “What you did on that day was wholly unforgivable to someone who clearly feels a lot about you.
“She simply wants you to get some help.
“You have got her to thank more than anybody else for not going to prison immediately.”