Mr Tan, of Songyuan city, says his 3ft high phone, which weighs 48lbs, is an exact copy of his own phone - but 620 times bigger.
A local journalist tested the phone by making calls and sending text messages and pronounced it completely functional, reports City News.
Tan says it has all the functions of a normal phone, with a built-in camera and internet access but has to be plugged into the mains as he hasn't managed to build a big enough battery.
"The only other difference is that I didn't incorporate the vibrate function," he said.
Tan, an electronics enthusiast, says he came up the idea for the giant phone a year and a half ago and finally started work on it with his father six months ago.
"Many friends worried I couldn't finish it, and only my father encouraged me to continue," he said.
"The neighbours were always knocking on my door asking what was going on with all the noise from the apartment, and even my wife was complaining." (City News)