The 18-year-old gave it her all but just couldn't land her run as competition favourite Chloe Kim of the USA won gold ahead of China's Jiayu Liu and USA's Arielle Gold.
Arthur had her best score in her opening run with a 48.25 before scoring 9.25 and 25.00 in her remaining two runs.
"It was amazing," said the Youth Olympic silver medallist.
"All of my family is here, it was so fun and I can't wait to do another one."
On her final time down the pipe, Arthur laid it all on the line as she attempted a backside 540, a trick she had never completed before in competition, midway through her run.
The young gun was extremely close to pulling it off but went down, hitting her head before making her way down the middle of the pipe and receving medical attention at the end of the run.
"I took a bit of a crash at the end of my third run but I'm so happy to be here.
"I pulled through and I'm still alive and I'm sure I'll be back on the snow in a couple of days.
"I'd never done that trick in comp before and I'm sure it would have paid if I'd landed it but I'm still happy."
Arthur had progressed through yesterday's qualification with a score of 66.50.
She was one of five Australians to win a Youth Olympic medal in Lillehammer 2016 when she claimed silver behind now Olympic Champion Chloe Kim.