Atiku also said that the only way the PDP would be able to restore its lost glory is to pick a formidable candidate for the 2019 presidential election.
He said Buhari has wasted his "massive goodwill" with the economic hardship Nigerians are experiencing everyday.
Atiku was quoted as saying this during an interview with Dele Momodu for his weekly column titled, 'Pendulum', published in The Boss Magazine.
He added, "I will definitely beat him this time. He has wasted a lot of his massive goodwill. A lot of people are disgruntled but they are keeping quiet and lying low. Our youths are suffering terribly. They are even now being sold into slavery.
"Everyone knows my track record of inviting and attracting a good team and giving them the opportunity to work professionally. Nigerians are tired of leaders who cannot think big and work big."
Atiku recently resigned from the ruling All Progressives Congress (APC), saying the party has failed Nigerians.
Although he maintained that he is yet to join any political party, he said the Peoples Democratic Party (PDP) is pressurizing him to join the party.
He said the only way the PDP would be able to restore its lost glory is to pick a formidable candidate.
"Nothing is absolutely certain in this life, but the PDP needs a candidate with the brightest chance and that can only come from someone who has major experience, exposure and knowledge about running an economy; who is a nationalist and not a sectionalist and whose brand cannot be intimidated in anyway by that of the current President.
"If the PDP picks a weak candidate, then the party is doomed. Some of those, whose names are being touted and bandied about, have not grown beyond their immediate domains," Atiku added.
He said Buhari's dictatorship style in the APC has stunted the progress of the party in the last two years.
The former vice president said he had advised the APC National Chairman, Chief John Odigie-Oyegun, to make some changes, adding that Oyegun refused to take action.
He added, "After Buhari won the election, he was no longer interested in the party that made him President. Every activity stopped and not even the party chairman, Chief John Oyegun, could take any decision.
"I called Chief Oyegun a few times to tell him that our party was dying slowly but he told me that he would not do anything unless he got a clearance from the President.
"At a stage, I gathered about 18 prominent members and began to meet in the hope that we can re-energise party activities, but some people lied to the President that I wanted to use the forum to launch my presidential campaign.
"That forum became simply dead on arrival. No BoT (Board of Trustees), no NEC (National Executive Committee) meetings, as stipulated in our constitution.
"The party became a one-man property. Everyone grumbles behind the President but they are too timid to raise a voice against the illegalities being perpetuated. I should be bold enough to know what I want, and can do so at my age. So, I decided to leave."
However, it is believed that Atiku will join the PDP before the party's December 9 national convention with the hope of securing the party's ticket for the 2019 presidential election.