Yellen, who would be the first women to hold this office, is expected to call lawmakers to action to sign off on more pandemic stimulus to get the economy back on track.
"Neither the President-elect, nor I, propose this relief package without an appreciation for the country's debt burden," Yellen will tell lawmakers, according to written testimony obtained by CNN. "But right now, with interest rates at historic lows, the smartest thing we can do is act big."
Biden last week proposed one of the largest relief packages in history -- worth $1.9 trillion -- in an effort to address the economic and public health crises he will inherit when he takes office on Wednesday.
Lawmakers have already enacted trillions of dollars in relief funds under President Donald Trump to address the crisis created by the coronavirus pandemic. But with job losses ticking up and millions still unemployed, Biden and congressional Democrats have made clear their first legislative priority will be a wide-ranging stimulus package.
"The pandemic has caused widespread devastation," Yellen says in her testimony. "The damage has been sweeping, and as the President-elect said last Thursday, our response must be, too."
Widespread support for Yellen
Yellen has widespread support for her nomination. All living former US Treasury secretaries called on Congress to swiftly confirm her.
"We believe that delaying the confirmation of our government's principal economic official would create unnecessary risk during this critical time," said the endorsement, signed by Republicans like Hank Paulson and John Snow as well as Democrats Robert Rubin and Larry Summers. It was released Tuesday ahead of the hearing.
The former officials warned that the United States faces "unprecedented economic conditions" that will require thoughtful engagement from the Treasury Department.
"Any gap in its leadership would risk setting back recovery efforts," according to the letter, which was also signed by James Baker, George Shultz, Tim Geithner and Jacob Lew.
Yellen, the first woman to lead the Federal Reserve, has the credentials required by the crisis, the former officials said.
"It is our view -- based on personal experience for many of us -- that Dr. Yellen's experience, knowledge, judgment, and character make her uniquely qualified for this role," the letter said.
The former Treasury secretaries pointed out that Yellen was previously confirmed by the Senate, most recently in 2014.
"It is hard to imagine a better prepared nominee to meet this great moment of need than Dr. Yellen," they wrote.
The hope is that Yellen's confirmation will reassure nervous allies overseas.
"Any delay in confirming Dr. Yellen will only allow concern and confusion to grow among our allies," the letter said.
-- CNN's Phil Mattingly and Matt Egan contributed to this report