The growing phenomenon of schools "turning away" students with special needs like autism and dyslexia must be stamped out, the Victorian Government says.

Next week's state budget will include a $156 million funding boost for special needs students, including upgrades for 20 specialist schools across the state.

The budget also sets aside $50 million to help an extra 1,700 students who are expected to be eligible for a disability program next year.

There is also $22 million for students with autism and dyslexia.

Education Minister James Merlino said the extra funding would mean there was no excuse for schools to refuse to accept students with special needs.

"There are many schools that do the right thing and they are fully inclusive, but we know it happens," he said.

"We hear it from parents and it's just got to stop."

Mr Merlino said there would be a focus on providing support staff across mainstream schools, to help special needs students stay in their local area.

"In practically every classroom there will be a child who is dyslexic, or there will be a child who is on the spectrum or a child with another learning difficulty," he said.

"That's why we need a focus on the capacity of our teachers and education support staff."