Laser sources that are high power, short time duration and broadly tunable are needed for the application of ultra-fast laser. Femtosecond optical parametric amplification is one of the important techniques to produce broadly tunable and several femtoseconds pulse. To produce extremely short laser pulse, the femtosecond optical parametric amplification should support large spectral bandwidth enough. The ultra-broadband optical parametric amplification of BBO type-Ⅰ phase matching is theoretically investigated. The achromatic phase matching technology is introduced in femtosecond optical parametric amplification, and broadband phase matching condition with angular dispersion of signal beam is given. The effects of noncollinear angle and angular dispersion of signal pulse on the phase mismatching and parametric bandwidth are also discussed. The results indicate that a suitable noncollinear angle of signal pulse and introducing suitable angular dispersion in near-infrared signal pulse can increase the parametric bandwidth dramatically. As an example, phase-matched noncollinear optical parametric amplifiers (NOPAs) pumped by the blue light of 400 nm are discussed. The method and the analysis results provide a theoretical guidance for obtaining broadband parametric amplifiers.