Some $349.6 million from Thursday's budget will go towards upgrading Thomas Embling Hospital, which predominantly provides services for people found not guilty of crimes on the grounds of mental impairment.

The works at the Fairfield facility will include a new dedicated 34-bed women's precinct and a 48-bed medium-security men's facility, as well as clinical administration facilities.

Acting Premier James Merlino, who is also the state's mental health minister, said one in three Victorian prisoners need treatment for psychological issues.

"Access to targeted, clinical care is critical to supporting these Victorians, and setting them on the path towards genuine recovery," he said in a statement on Monday.

A royal commission into Victoria's mental health system found the hospital has expanded "very slowly" despite the "very significant" expansion of the Victorian population and prison population, with just 36 additional beds created since 2002.

The royal commission recommended the government refurbish the existing 136 beds at the facility and provide an additional 107 by the end of 2026.

Mr Merlino said the upgrade will reduce wait times for mental health assessment and treatment, reduce incidents of deterioration and self-harm and increase access to services for female patients.

The government committed almost $900 million in last year's budget to overhaul the state's mental health system.

More funds are expected to be announced when Treasurer Tim Pallas hands down his seventh budget on Thursday.

The royal commission previously called for a new levy or tax to help pay for reform, but plans were put on hold due to the COVID-19 pandemic.

Meanwhile, $179.4 million from the 2021/22 budget has been allocated to stage one of the Fishermans Bend Innovation Precinct at the former General Motors Holden site.

The 32-hectare site, four kilometres from the Melbourne CBD, will from 2024 be the new home for the University of Melbourne's School of Engineering.

Stage one involves remediation of the site and installation of infrastructure, with a new road through the precinct.

"The old Holden factory is part of Victoria's manufacturing history - this important first step will help transform it into Victoria's manufacturing future," Business Precincts Minister Martin Pakula said.

The government also announced $44.1 million to expand the rollout of family violence programs and sexual assault support services for children and young people.

An additional $1.3 million will go towards supporting victims of family violence to ensure the safety of their pets.

Minister for the prevention of family violence Gabrielle Williams said 53 per cent of people experiencing family violence have reported their pets had been harmed.

Some are too scared to report or leave violent situations because they fear what will happen to their pets.

"For many people (they are) concerned about leaving their pet at home, concerned their pet may be injured or killed," Ms Williams said.

The government will provide financial assistance for kennels, cat baskets, vet care and accommodation.

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Australian Associated Press