More than a quarter of all exams sat at the Welton school resulted in A* and A passes, equalling the best ever year in 2015.
Pupils achieving three grades A* to C was 78 per cent, matching the highest ever set in 2016.
Half of all the grades achieved at the school were A* to B, with an average score of 31.3 UCAS points across all subjects.
Two thirds of Maths entrants recorded grades of at least B.
More than one in ten students also achieved A* to B in three “facilitating” subjects – twice the national average of six per cent.
Facilitating subjects are those deemed to be important by the UK’s leading universities and include English, History, Maths, Geography, languages and sciences.
Headteacher Andy Stones said he was thrilled that the school had achieved another set of excellent results.
He continued: “Every year I think the staff and pupils must have reached a pinnacle and every year the results come back even better than the last.
“I am so proud of what everyone here has achieved – not just this year but for several years.
“It just goes to show that if you set high standards and believe in the student’s ability to reach their potential then anything is possible.
“I have no doubt these students will go out into the world and achieve their goals.
“We wish them all the best.”