A hydraulic oil cylinder comprising: a cylinder barrel, a piston rod, a buffer sleeve, an elastic member and a piston, wherein the buffer sleeve is axially slidably sleeved on a piston rod additional section of the piston rod located in a rodless cavity of the cylinder barrel, and an end surface of the buffer sleeve facing a bottom of the cylinder barrel is a first end surface of the buffer sleeve; a rodless cavity sealing end surface is provided in an oil cylinder cavity of the hydraulic oil cylinder between a rodless cavity oil-passing hole of the hydraulic oil cylinder and an end position of a rodless cavity end surface of the piston in a retraction movement of the piston rod, and is configured to block the buffer sleeve and to abut against the first end surface of the buffer sleeve so as to form a sealing surface; and at least one throttling oil channel is further provided axially and linearly between the piston rod additional section and the buffer sleeve; such that during the retraction movement process of the piston rod, the hydraulic oil at a side of the sealing surface close to the piston can flow towards the rodless cavity oil-passing hole through the throttling oil channel in a period from a time when the first end surface of the buffer sleeve abuts against the rodless cavity sealing end surface to form the sealing surface to a time when the piston is retracted to an end position of the retraction movement, the elastic member, having elasticity and mounted in the rodless cavity, presses the buffer sleeve against a stop shoulder portion provided on a tail end of the piston rod additional section, characterized in that the throttling oil channel comprises two sections, a front section close to a second end of the throttling oil channel close to the rodless cavity oil-passaging hole is a throttling groove axially provided on a surface of the piston rod additional section, a rear section close to a first end of the throttling oil channel close to the piston is a hidden oil channel extending axially in the piston rod additional section, wherein the cross-sectional area of the throttling groove is gradually increased from the first end of the throttling oil channel close to the piston to the second end of the throttling oil channel close to the rodless cavity oil-passing hole, wherein a stop shoulder portion provided on a tail end of the piston rod additional section is a retaining key having two semicircular keys, an end surface of the retaining key close to the piston is provided with an annular groove, and an outlet of the throttling groove is communicated with the annular groove. a cylinder barrel, a piston rod, a buffer sleeve, an elastic member and a piston, wherein the buffer sleeve is axially slidably sleeved on a piston rod additional section of the piston rod located in a rodless cavity of the cylinder barrel, and an end surface of the buffer sleeve facing a bottom of the cylinder barrel is a first end surface of the buffer sleeve; a rodless cavity sealing end surface is provided in an oil cylinder cavity of the hydraulic oil cylinder between a rodless cavity oil-passing hole of the hydraulic oil cylinder and an end position of a rodless cavity end surface of the piston in a retraction movement of the piston rod, and is configured to block the buffer sleeve and to abut against the first end surface of the buffer sleeve so as to form a sealing surface; and at least one throttling oil channel is further provided axially and linearly between the piston rod additional section and the buffer sleeve; such that during the retraction movement process of the piston rod, the hydraulic oil at a side of the sealing surface close to the piston can flow towards the rodless cavity oil-passing hole through the throttling oil channel in a period from a time when the first end surface of the buffer sleeve abuts against the rodless cavity sealing end surface to form the sealing surface to a time when the piston is retracted to an end position of the retraction movement, the elastic member, having elasticity and mounted in the rodless cavity, presses the buffer sleeve against a stop shoulder portion provided on a tail end of the piston rod additional section, characterized in that the throttling oil channel comprises two sections, a front section close to a second end of the throttling oil channel close to the rodless cavity oil-passaging hole is a throttling groove axially provided on a surface of the piston rod additional section, a rear section close to a first end of the throttling oil channel close to the piston is a hidden oil channel extending axially in the piston rod additional section, wherein the cross-sectional area of the throttling groove is gradually increased from the first end of the throttling oil channel close to the piston to the second end of the throttling oil channel close to the rodless cavity oil-passing hole, wherein a stop shoulder portion provided on a tail end of the piston rod additional section is a retaining key having two semicircular keys, an end surface of the retaining key close to the piston is provided with an annular groove, and an outlet of the throttling groove is communicated with the annular groove.