The attack in the north-east Nigerian state also left seven persons injured.
Eyewitness said the suicide bomber, armed with Improvised Explosive Devices (IED) and AK47 rifle, launched an attack on the College.
The information department of the institution told Channels Television that the bomber attacked the college around 8:00am local time.
According to the school authority, the suicide bomber started shooting sporadically at the gate before entering the school, where he shot at students and teachers.
Reports say efforts were made to subdue the bomber when it was noticed that his ammunition was running out.
After apparently realising that he would be apprehended, the attacker triggered the IED he was carrying, killing himself in the process and injuring seven others.
Hospital sources said the seven persons, brought in with various degrees of gunshot injuries, have been hospitalised at the Potiskum General Hospital located just beside the school and are currently being treated.
The spokesman for the Police in the state command, Mr Toyin Gbadegesin, said that the situation had been brought under control and that security forces were working round the area to ensure the restoration of normalcy.
The entire school and other surrounding environment, covering the general hospital and the science school Potiskum have been condoned.
No group has claimed responsibility for the attack, but Boko Haram terrorists have carried out series of similar attacks in the past in the volatile north-east region.
Military assaults against the terrorists have increased after Nigeria postponed its election to enable the military reclaim communities that the Boko Haram terrorists were occupying in Adamawa, Borno and Yobe States. The electoral body said it was need to enable residents take part in the elections held on March 28 and April 11.
The military said it had reclaimed all communities in Yobe State under the control of the Boko Haram sect which had in the last five years tried to establish an Islamic caliphate in the region and also end western education.
Counter-terrorism efforts are now centred on the major stronghold of the terrorists, Sambisa Forest in Borno State, with the Army rescuing some women and children from the camps of the dissident group.