Det Supt Adam Hibbert told the hearing in Crawley a file was being submitted to the Crown Prosecution Service.
Sussex Police has been investigating pilot Andy Hill, 53, for possible manslaughter by gross negligence.
The date for the full inquest into the 2015 crash, which saw a jet plummet on to the A27, has been set for next year.
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Det Supt Hibbert told the hearing that a "conservative estimate" was that 25,000 documents in relation to the police investigation were now held on the force's database.
"We continue to talk with the families and I'm extremely grateful for their continued support and patience in what continues to be upsetting circumstances for them all," he said.
Mr Hill has been questioned voluntarily under caution by police.
The vintage Hawker Hunter jet crashed on to the dual carriageway while performing a looping manoeuvre during the Shoreham Airshow nearly two years ago.
West Sussex coroner Penelope Schofield said the inquest may have to be suspended pending the outcome of any criminal prosecution.
But she assured families at the hearing that she was was monitoring the police investigation.
She told them: "I want to assure you I am satisfied that they are moving forward as quickly as they can in quite difficult circumstances and they are hoping to bring their investigation to a conclusion as quickly as possible."
Speaking on behalf of the families after the hearing, Gerard Forlin QC said the families were very disappointed.
He said the crash had taken place more than 22 months ago.
"However what they want is a full, frank, thorough and fearless investigation into this incident," he added. "And of course for that they will wait as patiently as they can."
The police investigation into the Shoreham air disaster in which 11 men died is 95% complete, a pre-inquest hearing has been told.