More than 34,000 of the images and videos were in category A - the most extreme, North Yorkshire Police said.
Geoffrey George Crossland, 70, from Harrogate, had demonstrated a "long-standing interest in children", prosecutors told York Crown Court.
They said he "painstakingly categorised" the images and wrote lists of the best websites to view sexual pictures and videos of children.
The haul, saved on SD cards, laptops and tablets, is one of the largest known in England and Wales, according to the Crown Prosecution Service.
"More than 100 digital devices were seized from an office area above the underground bunker complex on Crossland's premises," said Detective Chief Inspector Graeme Wright.
Judge Andrew Stubbs QC said the "scale of the depravity" would be hard for the public to understand.
The "bunker", made from old shipping containers, was found when Crossland's home was searched on 18 October last year.
It contained weapons including a double-barrelled shotgun, two rifles and three revolvers, as well as 24,000 rounds of ammunition - including some expanding bullets.
There was also a shooting range and an area designed for the manufacture of ammunition.
Crossland's home was raided when he was on a shooting holiday in Argentina and police arrested him when he arrived back at Heathrow.
He repeatedly gave "no comment" answers during questioning.
Crossland later pleaded guilty to possessing the massive collection of indecent images and videos, as well as 11 charges relating to the possession of prohibited firearms
He was jailed for 12 years and eight months.
Marc Horsfall, from the National Crime Agency, said: "A team of specially trained NCA officers spent several months working through Crossland's horrific catalogue of abuse images to grade them in order of severity.
"Crossland and men like him are fuelling the actual contact abuse of children and the sickening distribution of those images."