  Coronal mass ejections (CMEs) and coronal jets are two types of common solar
eruptive phenomena, which often independently happen at different spatial
scales. In this work, we present a stereoscopic observation of a large-scale
CME flux rope arising from an unwinding blowout jet in a multipolar complex
magnetic system. Based on a multi-band observational analysis, we find that
this whole event starts with a small filament whose eruption occurs at a
coronal geyser site after a series of homologous jets. Aided by magnetic field
extrapolations, it reveals that the coronal geyser site forms above an elongate
opposite-polarity interface, where the emergence-driven photospheric flux
cancellation and repetitive reconnection are responsible for those preceding
recurrent jets and also contribute to the ultimate filament destabilization. By
interacting with overlying fields, the erupting filament breaks one of its legs
and results in an unwinding blowout jet. Our estimation suggests that around
1.4$-$2.0 turns of twist release in its jet spire. This prominent twist
transport in jet spire rapidly creates a newborn larger-scale flux rope from
the jet base to a remote site. Soon after its formation, this large-scale flux
rope erupts towards the outer coronae causing an Earth-directed CME. In its
source region, two sets of distinct post-flare loops form in succession,
indicating this eruption involves two-stage of flare magnetic reconnection.
This work not only reveals a real magnetic coupling process between different
eruptive activities but provides a new hint for understanding the creation of
large-scale CME flux ropes during the solar eruption.
