Judge Thorburn said it was a "grotesque act of cruelty".
"What I've read would be one of the cruellest acts I've ever heard of since I've been a judge."
Tao, who was assisted in court by a Chinese interpreter, will now likely be taken away from his wife and 11-month old baby and deported back to China.
The court heard previously the 6-month-old Pomeranian dog called Mia - which belonged to a friend of Tao's flatmate - had been left at an Auckland apartment on January 28 last year.
After finding the dog had defecated on his bed, Tao grabbed it and was then bitten, sparking a "momentary loss of control and fit of anger", according to his counsel.
Mia had trouble breathing and died shortly after the second attack, during which Tao threw three or four punches.
Later he burned the body at a west Auckland beach.
When interviewed by police he simply told them: "I go to the gym and practice boxing. My punch is very powerful."
Tao had previously completed 160 hours community work at Northcote Baptist Church's op-shop, his lawyer said, when the option of a discharge without conviction had been canvassed.
The community work was taken into account when Judge Thorburn handed him the sentence of 40 hours of community work.
He was also ordered to pay $2000 to the owner of the dog, which was "not a cheap puppy," Judge Thorburn said.
Tao had previously tried to pay the money to the dog's owner, but for an unknown reason it was not received.
