The deal with EDF Energy and the principal contractors Laing O’Rourke/Bouygues for a Common Framework Agreement enshrines direct employment for workers on site.
It also sets a minimum craft rate of £13 an hour for civil engineering work and bonus payments to establish the job as the best-paid site in the UK.
In another first workers will have pension payments match funded on the job.
The massive project is currently on hold awaiting a deal between EDF and the Government for how much electricity from the station will costs.
Once this is done construction proper is expected to start next year with the job employing 5,000 workers at the peak of construction.
After months of negotiating, unions UCATT, Unite and GMB have secured a Common Framework Agreement which addresses how industrial relations will be managed and a separate Civil Engineering Sector Agreement.
The Common Framework Agreement aims to combat casualisation and poor productivity by stipulating all site workers are directly employ through PAYE.
For the first time in such an agreement there will also be strict rules placed on the recruitment of workers through employment agencies.
A top of the range occupational health scheme will be established to help ensure the short-term and long-term health of the construction workforce.
The agreement sets a training target of at least 500 apprentices and adult trainees during the lifetime of the project.
The other Civil Engineering Sector Agreement establishes pay rates for the workforce significantly higher than those agreed by the Construction Industry Joint Council.
By the time work begins, which is expected to be in 2014, the craft rate will be at least £13 an hour.
The agreement also sets out provision for a bonus scheme, a productivity scheme and milestone payments, laying the foundations for what will be the best paid construction project the industry has seen.
In another first, the agreement establishes clear rules to ensure that workers will make and receive significant pension payments while working on the project.
Pension payments will begin at £10 per week of matched funding between employers and employees.
By January 2017, workers will see an amount equal to 10% of their pay being placed in their pensions, through 5% matched funding from employees and employers.
Steve Murphy, general secretary of construction union UCATT, said: “This groundbreaking agreement will ensure that workers building Hinkley Point will receive excellent rates of pay and first class conditions.
“This agreement will act as the blueprint for all future major construction projects.”
Kevin Coyne, Unite national officer for energy and utilities, said: “This agreement sends a clear message to the rest of the construction industry that good productive relationships can deliver positive results.
“The unions and employers have made real progress in laying the right foundations for this important project.
“It is now time for the government to stop delaying and give EDF the certainty it needs so the company can get on with the job of meeting the UK’s energy needs.”