Spending is projected at 11.9bn riyals ($30.9bn) in 2016 compared with $36.6bn, a statement from al-Balushi said.
Revenues are projected at 8.6bn riyals ($22.3bn), down a massive 26% from 2015, resulting in a deficit of $8.6bn, said the statement cited by the official ONA news agency.
Oman's deficit last year was $11.7bn.
Gulf states have been hit hard by a cash crunch due to a 65% drop in oil prices since June 2014.
Most of them have introduced austerity measures, and Oman said on Wednesday it has decided a series of measures to boost non-oil revenues.