Work at the site off Geraldine Road is due to start within the next few weeks afterWorcestershire County Council invested £3.5m and Malvern Hills District Council£370,000.
The new development, known as Phase Four, will provide a new home for one of the park's existing tenants, UTC Aerospace Systems. This will free up the space that the company is currently occupying for new tenants.
Carrying out the work will be Birmingham-based contractor Trebor Developments, with the new building expected to be finished in autumn 2015.
Science park chief executive Alan White said: "The commencement of Phase Four consolidates our ever-growing reputation as one of the UK's leading centres for defence technologies. UTC's relocation will also create opportunities for smaller businesses to move onto the park with the potential to create 150 new jobs."
Simon Geraghty, deputy leader of Worcestershire County Council, said: "Historically Malvern has been a hub for the development of new technology and this continues today.
"The science park has been really successful and this further phase of development will allow even more space for existing firms to grow and to accommodate new start-up companies."
Cllr Phil Grove, economic development portfolio holder at Malvern Hills District Council, said: "The science park is now home to a number of businesses and well over 300 high-value jobs. The district council recognise its potential and are delighted to support the next phase of development as part of the council’s economic development priority."