Testing will be taking place from tomorrow (Tuesday, May 12) to Thursday (May 14).
The Lancashire Resilience Forum, which is supported by police, fire, health and local authorities, has arranged for the return of testing to Lancaster.
Organised by the Department of Health and Social Care with help from the armed forces, the site can accommodate around 250 people per day.
In recent weeks, Lancaster has had one of the highest infection rates in the UK, with 746 people testing positive for coronavirus to date.
But the chief officer at Morecambe Bay's health trust, Aaron Cummins, has urged caution over the way the figures can be interpreted.
"It is difficult to carry out a like for like comparison for different areas because of the different age structures and other socio-demographic factors, and of course, the varying levels of testing that have been carried out.
"As a Trust, we have been testing our colleagues and their family members, and other key workers for a significant amount of time and in large numbers.
"It is important that these figures are viewed in this context.
"Further investigation of all the data, including figures from the national testing centres that opened recently, needs to be carried out before any real conclusions can be made.
"However, it does highlight the point that the work is not over yet."
Testing has previously taken place at the car park in St Leonardsgate, where appointments are required to attend.
The Lancashire Resilience Forum is reminding people that those seeking a test must not just turn up, but should book it through the Government website here.
Dr Sakthi Karunanithi, director of public health for Lancashire, has explained why testing is so important in the battle against coronavirus.
He said: "We know that this situation is a difficult time for people. Through testing we can understand more about the scale of this situation and help us to bring normal life back again, once it's appropriate to do so.
"Mobile testing sites helps us to prioritise certain areas, by adding additional capacity for a short time where it will have the most benefit.
"By testing key workers and their families if they're showing symptoms, we can keep vital services running at this time and protect the key workers themselves."
Other testing sites are already in operation at Preston College and Royal Blackburn Hospital.
The Lancashire Resilience Forum said it working closely with partner organisations to create additional mobile and satellite testing sites in the county. This includes mobile testing for care home staff.
You can find out more or book a coronavirus test by visiting the Government website here.