The vintage steam train's 2011-12 season ended at the weekend, having attracted almost 16,000 visitors, after Mr Bryce bought the train last year.
Mr Bryce said the community support and high visitor numbers in its first season back in operation had given him confidence in the future of the business.
People could subscribe to be members of the trust for $100 annually, giving them and five others half-price train rides at any time.
Subscription fees and donations would go towards the preservation of the Kingston Flyer locomotives, carriages, railway lines and buildings, which the trust would own.
Mr Bryce would also form a board of trustees to manage the trust.
"I'm approaching some high-profile New Zealand business people, tourism experts and train buffs to be on the trust to ensure its future as a very important, historic asset.
"This will be a charitable trust that will be set up in such a way that individuals can subscribe to become members, and volunteers can come and work for it," he said.
The Kingston Flyer 2012-13 season will start on September 29, with two trips a day.